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arti d8d54bb990 feat(xie): a client-chosen XIE image is displayed on the VT1200 
The XIE path now runs end to end: XieCreateImage -> XieCreatePhoto ->
XiePutTile -> XieExport(photomap -> depth-1 pixmap) -> XCopyArea(pixmap ->
window), and the client's tile appears on screen at the client's own window
position, pixel-exact.

TWO FAULTS BEHIND THE LONG DEAD END

1. Device model (harness/mame/vt1200.cpp, opt-in VT1200_ACCEL=1).  The
   accelerator's output port 0x5600200 returns the pixel stream the firmware
   pushed into the FIFO -- the firmware then stores it into the drawable itself
   (file 0x125528: MOVE *B6,*B1 ; ADDK 0x10,B1).  The FIFO read pointer was
   never reset between transfers, so consecutive exports read stale words and
   the same fill produced 759 then 516 set pixels.  Reset m_fifo_in/out on the
   data-register write; the export is now deterministic.

2. Measurement, not the device.
   - dwt/screenshot.py without --real reads 1024x1024 at a 128-byte row stride,
     but the VR319 default programs 1280x1024 at a 2048-bit (256-byte) pitch.
     That is the "shifted" picture; --real is the correct read.
   - The earlier "0 differing bytes over 128 KiB" VRAM comparison stepped peek
     by 1024 *bit* addresses, so it scanned rows 0..63 only -- never the window
     at rows 200..263.  Over the real raster the white/black diff is 576 bytes
     spanning exactly those rows.
   - New instrument: decclient does a server-side XGetImage readback of the
     pixmap and window and counts set pixels.  That separated "the server never
     drew it" from "the framebuffer view is wrong".

EVIDENCE (reproduced twice, the second time from a fresh machine)

  no export vs 0xFF : 4096 / 4096 pixels differ
  no export vs 0x00 :    0 / 4096   (the window background is black)
  0xFF      vs 0x00 : 4096 / 4096
  0xAA      vs 0x0F : 2048 / 4096   (the two stripe phases)

Tile byte 0xAA reproduces as 1-pixel vertical stripes, 0x0F as 4-pixel, with
no shear -- so the placement is right and the pixels are the client's.

Contents: xie/ holds DEC XIE 2.3 headers, 84 man pages and complete
client+server source; a libXie.a and decclient built from DEC's own code; the
XIE probes; and evidence/ with every measurement, including explicit
retractions of the earlier wrong readings (VRAM_IDENTICAL_FOR_BOTH_FILLS and
friends).  xie/evidence/XIE_IMAGE_DISPLAYED.md is the report; frames are in
xie/evidence/png/.

The accelerator model stays opt-in: it answers the status poll and relays the
pixel stream, but performs no compositing, so it is a stand-in and the verified
default configuration is unchanged (a no-env run still parks in the level-0
diagnostics menu at PC=3FDCE400).
2026-11-01 23:22:25 +02:00

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X Image Extension Protocol
Publication Description:
This document describes the protocol of the X WINDOW SYSTEM IMAGE EXTENSION.
Version 5.02
X Consortium Standard
X Version 11, Release 6.3
December 16, 1996
Copyright © 1988, 1989, 1990, 1991, 1992 Digital Equipment Corporation
Copyright © 1990, 1991, 1992, 1993, 1994 X Consortium, Inc.
Copyright © 1992, 1993, 1994 AGE Logic, Inc.
Permission to use, copy, modify, distribute, and sell this documentation for any purpose
is hereby granted without fee, provided that the above copyright notices and this permis-
sion notice appear in all copies. Digital, the X Consortium, and AGE Logic make no
representations about the suitability for any purpose of the information in this document.
This documentation is provided as is without express or implied warranty.
Contents
Contents iii
Preface x
Related Documents x
Participants xi
Authors: xi
Contributors: xi
Revision History xi
Organization xii
Introduction xii
Protocol Parameter Types and Syntax xii
Protocol Requests and Replies xii
Pipeline Elements xii
Events and Errors xii
Techniques xii
Service Classes xii
Protocol Encodings xii
Acknowledgments xiii
Introduction 1-1
Scope and Purpose 1-1
Terminology 1-1
Techniques 1-1
Service Classes 1-1
Specification Syntax 2-1
General Syntax 2-1
Request Syntax 2-2
Requests without a Reply: 2-2
Requests with a Reply: 2-2
Syntax of Photo Elements 2-3
Photo Elements: 2-3
Syntax of Events 2-4
Events generated by Photo Elements: 2-4
Syntax of Errors 2-4
Core X errors 2-4
XIE non-Photoflo errors: 2-4
XIE Photoflo related errors: 2-4
Syntax of Protocol Encodings 2-5
Requests 2-5
Replies 2-5
PhotoElements 2-5
Events 2-6
Errors 2-6
Parameter Types 3-1
XIE and Core X Types 3-1
Techniques 3-1
Definitions 3-2
XieTypAlignment 3-2
XieTypArithmeticOp 3-2
XieTypColorAllocTechnique 3-3
XieTypColorList 3-3
XieTypCompareOp 3-3
XieTypConstant 3-4
XieTypConstrainTechnique 3-5
XieTypConvertFromRGBTechnique 3-5
XieTypConvertToRGBTechnique 3-5
XieTypConvolveTechnique 3-6
XieTypDataClass 3-6
XieTypDataStream 3-6
XieTypDataType 3-6
XieTypDecodeTechnique 3-7
XieTypDitherTechnique 3-7
XieTypEncodeTechnique 3-8
XieTypExecutable 3-8
XieTypExportNotify 3-9
XieTypExportState 3-9
XieTypFloat 3-9
XieTypGamutTechnique 3-10
XieTypGeometryTechnique 3-10
XieTypHistogramData 3-11
XieTypHistogramShape 3-11
XieTypInterleave 3-11
XieTypLevels 3-12
XieTypLUT 3-12
XieTypMathOp 3-12
XieTypMatrix 3-12
XieTypOrientation 3-13
XieTypPhotoElement 3-14
XieTypPhotoflo 3-14
XieTypPhotofloOutcome 3-14
XieTypPhotofloState 3-15
XieTypPhotomap 3-15
XieTypPhotospace 3-15
XieTypPhototag 3-15
XieTypProcessDomain 3-16
XieTypRectangle 3-16
XieTypROI 3-16
XieTypServiceClass 3-17
XieTypTechniqueGroup 3-17
XieTypTechniqueRec 3-18
XieTypTile 3-18
XieTypTripletoftype 3-18
XieTypWhiteAdjustTechnique 3-19
Resources 4-1
Overview 4-1
Binding Resources to Photoflos 4-1
ColorList resources 4-1
LUT, Photomap, and ROI resources 4-1
Resource destruction 4-2
Synchronizing resource access 4-2
Capability Acquisition 4-3
QueryImageExtension 4-3
Technique Acquisition 4-4
QueryTechniques 4-4
ColorList 4-5
CreateColorList 4-5
DestroyColorList 4-5
PurgeColorList 4-6
QueryColorList 4-6
LUT 4-7
CreateLUT 4-7
DestroyLUT 4-7
Photomap 4-8
CreatePhotomap 4-8
DestroyPhotomap 4-8
QueryPhotomap 4-9
ROI 4-10
CreateROI 4-10
DestroyROI 4-10
Pipelined Processing 5-1
What is a Photoflo? 5-1
Two kinds of Photoflos 5-2
Multi-client Photoflos 5-2
Photoflo States 5-3
Flo'ing Data to a Resource 5-3
Name space 5-4
CreatePhotospace 5-4
DestroyPhotospace 5-4
Immediate Photoflos 5-5
ExecuteImmediate 5-5
Stored Photoflos 5-6
CreatePhotoflo 5-6
DestroyPhotoflo 5-6
ExecutePhotoflo 5-7
ModifyPhotoflo 5-8
RedefinePhotoflo 5-8
Sending Data to the Server 5-9
PutClientData 5-9
Retrieving Data from the Server 5-10
GetClientData 5-10
Status 5-11
QueryPhotoflo 5-11
Synchronization 5-12
Await 5-12
Termination 5-12
Abort 5-12
Import Elements 6-1
Overview 6-1
Element categories 6-1
Multi-source images 6-1
Events generated 6-1
Import from Client 6-1
ImportClientLUT 6-2
ImportClientPhoto 6-3
ImportClientROI 6-4
Import from Resource 6-5
ImportDrawable 6-5
ImportDrawablePlane 6-6
ImportLUT 6-7
ImportPhotomap 6-8
ImportROI 6-9
Process Elements 7-1
Overview 7-1
Limiting the Process 7-1
Process Selected Bands 7-1
Process Intersecting Pixels 7-1
Process Selected Pixels 7-2
Data Types 7-2
Process Categories 7-3
Process Definitions 7-3
Arithmetic 7-4
BandCombine 7-5
BandExtract 7-6
BandSelect 7-7
Blend 7-8
Compare 7-9
Constrain 7-11
ConvertFromIndex 7-12
ConvertFromRGB 7-13
ConvertToIndex 7-14
ConvertToRGB 7-15
Convolve 7-16
Dither 7-17
Geometry 7-18
Logical 7-20
MatchHistogram 7-22
Math 7-23
PasteUp 7-24
Point 7-25
Unconstrain 7-26
Export Elements 8-1
Element categories 8-1
Export to Client 8-1
Events generated 8-1
ExportClientHistogram 8-2
ExportClientLUT 8-3
ExportClientPhoto 8-4
ExportClientROI 8-5
Export to Resource 8-6
ExportDrawable 8-6
ExportDrawablePlane 8-7
ExportLUT 8-8
ExportPhotomap 8-9
ExportROI 8-10
Events and Errors 9-1
Events 9-1
ColorAlloc 9-1
DecodeNotify 9-2
ExportAvailable 9-2
ImportObscured 9-3
PhotofloDone 9-3
Resource Errors 9-4
Photoflo errors 9-5
Techniques A-1
Standard and Private Techniques A-1
Technique numbers A-1
Technique names A-1
Default Techniques A-2
Technique parameters A-2
Technique information A-2
Color Allocation Techniques A-3
Constrain Techniques A-4
Convert From RGB A-5
Convert To RGB A-6
Convolution Edge Techniques A-8
Decode Techniques A-9
Dithering Techniques A-13
Encode Techniques A-14
Gamut Compression Techniques A-18
Geometry Techniques A-19
Histogram Shapes A-27
White Point Adjustment Techniques A-28
Service Class B-1
Full B-1
DIS B-1
Service Class Summary B-2
Protocol Encodings C-1
Extension Name C-1
Types C-1
Requests and Replies C-9
Import Elements C-15
Process Elements C-17
Export Elements C-22
Technique Parameters C-24
Events C-32
Errors C-34
Figures and Tables
Figure 1-1 Service Classes defined in this document 1-2
Figure 4-1 Creating and populating a new Photomap 4-1
Figure 4-2 Process image from Photomap a, place result into Photomap b 4-2
Figure 4-3 Process image from Photomap a "in-place\ 4-2
Figure 5-1 Photoflo element input and output connections 5-1
Figure 5-2 Example Photoflo 5-2
Figure 5-3 Photoflo states 5-3
Figure 7-1 Combining two sources using a control plane Logical: NoOp 7-2
Figure 7-2 A sample geometric transform: crop and scale 7-18
Figure 7-3 Background fill used for pixels beyond the edge 7-19
Figure 7-4 Point's algorithm for computing combined LUT indices 7-25
Figure A-1 Diagram of the ErrorDiffusion algorithm A-13
Figure A-2 Effect of sampling technique when scaling to a lower pixel density A-20
Figure A-3 Illustration of an output pixel mapping back to the input image A-21
Figure A-4 Sequence producing an antialiased image using a low-pass filter A-22
Figure B-1 DIS sources, operators, and destinations B-1
Table 3-1 Technique naming and numbering conventions 3-1
Table 3-2 Treatment of floating point parameters passed through the protocol 3-4
Table 5-1 Examples of two element Photoflo usage 5-3
Table 6-1 Relationship between LUT class and image class 6-2
Table 7-1 Compare parameter and DataClass dependencies 7-9
Table 9-1 XIE Error codes 9-4
Table 9-2 Photoflo error subcodes 9-5
Table B-1 Types itemized by ServiceClass B-2
Table B-2 Techniques itemized by ServiceClass B-4
Table B-3 Requests itemized by ServiceClass B-5
Table B-4 Import elements itemized by ServiceClass B-6
Table B-5 Process elements itemized by ServiceClass B-6
Table B-6 Export elements itemized by ServiceClass B-6
Table B-7 Events itemized by ServiceClass B-7
Table B-8 Errors itemized by ServiceClass B-7
Preface
The X architecture was a major step towards defining open, interactive application display services. X
pried apart the tightly coupled, private interconnect that has existed between application and display
subsystem by specifying a minimal, structured service set.
To retain a consistent, minimal core service set and yet accommodate evolving application require-
ments, X provides a method for extending the core protocol with additional domain specific requests.
This document defines an X extension for the imaging domain. It is the fifth version of the X Image
Extension Protocol proposal and, as prior readers will immediately recognize, it is a lineal descendent
of the other four.
Because the purpose of this document is to provide a clear, concise articulation of the protocol, ex-
pository materials have been pared to a bare minimum. It is assumed that the reader has a measure of
conceptual knowledge about imaging.
Readers who lack familiarity with the X Window System are encouraged to begin with a selection
from the related documents given below.
Related Documents
X Window System (Scheifler & Gettys)
The complete reference to Xlib, X protocol (and extension conventions), ICCCM, XLFD.
Digital Press
X Protocol Reference Manual (Nye, editor)
The Definitive Guides to the X Window System, Volume 0.
OReilly & Associates, Inc.
The X Window System Server (Israel & Fortune)
Guide to the X sample server: architecture, porting and tuning, writing extensions.
Digital Press
XIE Sample Implementation Architecture (Shelley, Verheiden & Fahy)
An overview of the architecture of the XIE sample implementation.
AGE Logic, Inc.
XIElib Specification (Rogers)
Reference pages for the XIE client library functions.
AGE Logic, Inc.
Participants
Authors:
Robert NC Shelley Digital Equipment Corporation
Robert W. Scheifler X Consortium, Inc.
Ben Fahy Visionary Software, Inc.
Jim Fulton Network Computing Devices, Inc.
Keith Packard Network Computing Devices, Inc.
Joe Mauro Digital Equipment Corporation
Richard Hennessy Avid Technology, Inc.
Tom Vaughan Digital Equipment Corporation
Contributors:
Gary Grebus Digital Equipment Corporation
Larry Hare NetManage, Inc.
Peter Kaczowka Hewlett-Packard Co.
Jeffrey Siegal Congruent Corporation
Al Tabayoyon North Valley Research, Inc.
John Weber Big Time Software, Inc.
Revision History
rev v1.0 August 1, 1988 first protocol draft
rev v2.0 April 12, 1989 major changes based upon consortia review
rev v2.1 November 1, 1989 changes based upon FT1 implementation
rev v2.2 March 15, 1990 changes based upon FT2 implementation (pipes)
rev v3.0 October 1, 1990 changes in preparation for consortia review
rev v4.0 June 1, 1991 changes based upon consortia technical review
rev v4.08 May 29, 1992 preliminary imagework review copy
rev v4.09 June 9, 1992 imagework review copy for meeting at San Jose
rev v4.10 September 10, 1992 pre-review of encodings and contributions
rev v4.11 October 31, 1992 imagework review with initial definition of DIS
rev v4.12 December 23, 1992 initial Public Review copy
rev v4.13 May 19, 1993 changes made during Alpha phase of sample implementation
rev v4.14 October 20, 1993 changes made during Beta phase of sample implementation
rev v4.15 December 15, 1993 changes made prior to final release of sample implementation
rev V5.0 January 10, 1994 final draft
rev V5.0 April 18, 1994 cosmetic cleanup prior to releasing X11 R6
rev v5.01 July 5,1996 incorporate Digital Press edits
rev v5.02 December 16, 1996, incorporate additional Digital Press edits and X11 R6.3
Organization
This document is organized into the following chapters and appendices:
Introduction
Chapter 1 Explains the purpose of the X Image Extension (XIE).
Protocol Parameter Types and Syntax
Chapter 2 Defines protocol syntax (how the protocol is encoded on the wire).
Chapter 3 Defines types for protocol parameters.
Protocol Requests and Replies
Chapter 4 Describes the resources used by the XIE protocol and library.
Chapter 5 Describes pipelines, client data transport, and pipeline utility requests.
Pipeline Elements
Chapter 6 Describes pipeline elements used for data import.
Chapter 7 Describes the general processing elements used in pipelines.
Chapter 8 Describes pipeline elements used for data export.
Events and Errors
Chapter 9 Describes events and errors returned from XIE.
Techniques
Appendix A Describes the XIE standard techniques and their parameters.
Service Classes
Appendix B Summarizes required, optional, and excluded items for each XIE service class.
Protocol Encodings
Appendix C Provides the complete protocol encoding for all XIE: types, requests, replies, ele-
ments, techniques, events, and errors.
Acknowledgments
We are all indebted to Digital Equipment Corporation where the X Image Extension was originally
conceived. They persevered through numerous protocol reviews and revisions and provided the ini-
tial sample implementations. Their efforts contributed greatly towards promoting XIE into the Public
Review process.
This document evolved from original specifications authored by Joe Mauro. We hope that it still
shows some of his architectural strength and elegance. The majority of the current document
(through version 4.11) was authored by Bob Shelley while employed at Digital. Subsequent revisions
were made at AGE Logic.
The current view of pipelines emerged almost completely intact from a single, terse email message
from Bob Scheifler and Keith Packard.
The need for robust geometric transforms was first promoted by Ben Fahy. We are grateful that he
has provided us with detailed documentation for the basic geometry element and several retrospective
sampling algorithms.
While one could debate that XIE is too big or too small, we can thank Jim Fulton for spearheading
the effort to define a smaller gentler XIE, the Document Imaging Subset.
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xiv
1
Introduction
Scope and Purpose
This document specifies the X wire protocol for the X Image Extension (XIE). It defines the syntax,
structure, and semantics of XIE protocol elements. It does not contain background material on im-
aging concepts that the protocol extension enables, nor does it contain any language specific bindings.
Terminology
This specification contains a certain amount of descriptive terminology that is commonly used within
the image processing community. There is also parametric terminology that is used to describe the
parameter types recognized by the core X protocol and the image extension protocol. The image ex-
tension protocol types are defined in this document.
Techniques
For some XIE operations, there are several recognized algorithms or techniques that offer varying
tradeoffs between quality of results and performance. Also, in some cases, different techniques are
required due to an image's class or content. To accommodate some flexibility in this area, such XIE
operations accept a technique parameter. A description of the techniques specified in this document
can be found in Appendix A. Individual implementations may extend XIE's capabilities by providing
additional techniques to provide for particular market needs.
Service Classes
For some environments, such as simple document image viewing, the full set of services provided by
XIE may include features that are not needed by the target applications. In such situations
(particularly for entry-level monochrome displays), server implementors may wish to provide only a
subset of the full XIE protocol.
Subsets are arranged in a nested hierarchy of service classes. Each service class includes all of the
features of any subsets that it surrounds (similar to the layers of an onion). Thus, applications written
to use a given subset of the protocol will function correctly when running on servers that implement
an enveloping service class.
This version of the XIE protocol defines two class: the full protocol (Full), and a document imaging
subset (DIS). Future versions of the XIE protocol may define additional service classes.
Figure 1-1 Service Classes defined in this document
For a complete list of types, techniques, protocol requests, pipeline elements, events, and errors that
are included in DIS, see Appendix B.
Introduction 1-1
2
Specification Syntax
This section presents syntactic conventions that are adhered to throughout this specification.
General Syntax
In general, the extension package follows the X11 protocol syntax conventions. Additions to this
syntax are as follows:
* The syntax ( . . . ) encloses a set of alternative values.
* The syntax [ . . . ] encloses a set of structure components.
* Within definitions the following prefixes are used:
XieReq: Protocol request/reply (for example, XieReqCreatePhotoflo)
XieFlo: Photoflo element (for example, XieFloConvolve)
XieEvn: Protocol event (for example, XieEvnPhotofloDone)
XieErr: Protocol error (for example, XieErrPhotospace)
XieTyp: Protocol type (for example, XieTypProcessDomain)
XieVal: Alternative value (for example, XieValBandByPixel)
* Outside of definitions the prefixes are generally not used:
Alternative values are italicized and bold (for example, BandByPixel)
All others are capitalized and bold (for example, CreatePhotoflo)
* Core X types are displayed in upper-case (for example, COLORMAP, WINDOW)
Request Syntax
Requests without a Reply:
XieReqRequestName
arg-1: type-1 1st argument for RequestName
. . .
arg-N: type-N N-th argument for RequestName
Errors: none or list of errors specific to RequestName (for example, FloID)
Events: none or list of events generated by RequestName (for example, PhotofloDone)
Overview Describes the basic function of the request.
Parameters Lists the parameters and gives a brief description of each.
Semantics Interrelationships between input data, parameters, and output results.
Errors Table of errors that can be generated and their causes, for example:
Error Cause
error-1 Circumstances that generate error-1
. . .
error-N Circumstances that generate error-N
Requests with a Reply:
XieReqRequestName
arg-1: type-1 1st argument for RequestName
. . .
arg-N: type-N N-th argument for RequestName
*
result-1: type-1 1st reply result from RequestName
. . .
result-M: type-M M-th reply result from RequestName
Errors: none or list of errors specific to RequestName (for example, Photomap)
Events: none or list of events generated by RequestName (for example, EventName)
Overview Describes the basic function of the request.
Parameters Lists the parameters and gives a brief description of each.
Reply data Lists the parameters and gives a brief description of each.
Semantics Interrelationships between input data, parameters, and output results.
Errors Table of errors that can be generated and their causes, for example:
Error Cause
error-1 Circumstances that generate error-1
. . .
error-N Circumstances that generate error-N
Syntax of Photo Elements
PhotoElements occur within XIE pipelines (see following chapters for clarification). The syntax of
these elements is as follows:
Photo Elements:
XieFloElementName
src-1: src-type-1 1st source for ElementName (if required)
. . .
src-N: src-type-N N-th source for ElementName (if required)
param-1: param-type-1 1st parameter for ElementName
. . .
param-M: param-type-M M-th parameter for ElementName
Errors: none or list of errors specific to ElementName (for example, FloAlloc)
Events: none or list of events generated by ElementName (for example, ExportAvail
able)
Attributes Table of PhotoElement output attributes, for example:
Attribute Value
class DataClass of output data
SingleBand achromatic or index
TripleBand trichromatic
type DataType:
Constrained quantization levels is levels (integer data)
Unconstrained quantization levels is unknown (may be float data)
width Width of output data (in pixels per band)
height Height of output data (in pixels per band)
levels Depends on type:
Constrained number of quantization levels (per band)
Unconstrained unknown
Overview Describes the basic function of the photo element.
Parameters Lists the parameters and gives a brief description of each.
Semantics Interrelationships between input data, parameters, and output results.
Errors Table of errors that can be generated and their causes, for example:
Error Cause
error-1 Circumstances that generate error-1
. . .
error-N Circumstances that generate error-N
Syntax of Events
Events generated by Photo Elements:
XieEvnEventName
instance: XieTypExecutable < Photoflo instance generating EventName >
phototag: XieTypPhototag < event Phototag (0 for general Photoflo event) >
type: CARD16 < element type (0 for general Photoflo
event) >
value-1: type-1 < 1st value returned by EventName >
. . .
value-N: type-N < N-th value returned by EventName >
Overview Description of the event.
Values returned Description of the values returned.
Syntax of Errors
Errors can be associated with core X11 resources or XIE resources. In the case of XIE specific error
conditions, a distinction is made between errors related to a Photoflo and those that are not.
Core X errors
Normal X errors (with XIE major/minor opcodes) are used where appropriate (for example, Alloc).
XIE non-Photoflo errors:
XieErrName
xie-error: XieErrName < error code of Name, offset from first-error >
resource-id: XID < resource to blame, for example, Photomap >
detail < 21 bytes available for additional error detail >
Overview Description of the error.
Values returned Description of the values returned.
XIE Photoflo related errors:
XieErrFloName
flo-error: XieErrName < error code for Flo, offset from first-error >
flo-id:CARD32 < executable flo-id>
flo-code: XieErrFloName < specific error type >
name-space: CARD32 < executable name-space>
phototag: CARD16 < erring Phototag (0 for general Photoflo error) >
type: CARD16 < element type (0 for general Photoflo er-
ror) >
detail < 12 bytes available for additional error detail >
Overview Description of the error.
Values returned Description of the values returned.
Syntax of Protocol Encodings
Requests
# of Bytes Value Description
1 CARD8 XIE major opcode
1 CARD8 XIE minor opcode
2 CARD16 Request length (total bytes divided by 4)
N Parameters required by the minor opcode
< 4 Pad (if required)
Requests consist of four (4) bytes of header followed by zero (0) or more additional bytes of data. If
additional bytes of data are needed the entire request is padded to a multiple of four (4) bytes. The
common fields (major/minor opcode and length) are not included in XieReq request definitions.
Bytes not used by a specific minor opcode are not guaranteed to be zero.
Replies
# of Bytes Value Description
1 1 Reply
1 Available for reply data
2 CARD16 Sequence number of corresponding request
4 CARD32 Reply length (extra data bytes divided by 4)
24 Available for reply data
N Extra data beyond standard reply packet
< 4 Pad (if required)
Replies consist of thirty-two (32) bytes followed by zero (0) or more extra bytes of data. If extra bytes
of data are needed the entire reply is padded to a multiple of four (4) bytes. The common fields
(Reply, sequence number, and length) are not included in XieReq reply definitions. Bytes not used by
the reply from a specific request are not guaranteed to be zero.
PhotoElements
# of Bytes Value Description
2 CARD16 Element type
2 CARD16 Element length (bytes divided by 4)
multiple of 2 XieTyp(Phototag|Tile) Element's data source(s) (if required)
N Parameters as required by element type
< 4 Pad (if required)
A photo element consists of four (4) bytes of header followed by zero (0) or more bytes of element in-
put connection definitions and by zero (0) or more bytes or additional data. The entire element defi-
nition is padded to a multiple of four (4) bytes. The common fields (element type and element length)
are not included in XieFlo element definitions. Bytes not used by a specific element type are not
guaranteed to be zero.
Note: PhotoElements are not protocol requests but, rather, subpackets within another protocol request (that is, ExecuteImmediate,
CreatePhotoflo, ModifyPhotoflo, or RedefinePhotoflo).
Events
# of Bytes Value Description
1 CARD8 XIE event code
1 <varies> <event-specific>
2 CARD16 Sequence number
4 TIMESTAMP Time
24 <varies> <event-specific>
Events consist of thirty-two (32) bytes. The common fields (event code, sequence number, and time)
are not included in XieEvn definitions. Bytes not used by a specific event code are not guaranteed to
be zero.
Errors
# of Bytes Value Description
1 0 Error
1 CARD8 XIE error code
2 CARD16 Sequence number
4 <varies> <error-specific (often a resource-id)>
2 CARD16 Minor opcode
1 CARD8 Major opcode
21 <varies> <error-specific>
Errors consist of thirty-two (32) bytes. Bytes not used by the specific error code are not guaranteed to
be zero.
Protocol Specification Syntax 2-1
3
Parameter Types
XIE and Core X Types
X Image Extension types are defined in this section. All XIE parameters are defined as being either one
of the extension types or one of the core protocol types. XIE makes use of the following core protocol
types (defined in the X11 core protocol specification):
BITMAP BOOL CARD8 CARD16
CARD32 CHAR2B COLORMAP DRAWABLE
EVENT GCONTEXT INT8 INT16
INT32 PIXMAP STRING8 TIMESTAMP
VISUAL WINDOW XID*
* XID is used to refer to the core X11 type defined as the identifier for a resource.
Techniques
Several standard techniques are defined in this document. Each is assigned a technique number and a de-
scriptive name string. XIE can also be extended with private techniques that are implementation depend-
ent. Private technique numbers are generated dynamically. Private technique name strings include the
name of the organization that defined the technique. The organization name is encompassed by _
(underscore) characters. Technique naming and numbering conventions are summarized in Table 3-1.
standard technique
private technique
name
<standard-technique-name>
example: ERROR-DIFFUSION
_<organization-name>_<private-technique-name>
example: _PHOTOCO_SQUASH-BITS
number
MS bit is zero (range: 0 - 32767)
MS bit is one (range: 32768 - 65535)
Table 3-1 Technique naming and numbering conventions
The technique number is supplied to pipeline elements to specify the desired technique. Numbers for
standard techniques can be hard-coded, whereas numbers for private techniques must be obtained using
the QueryTechniques protocol request.
For more information on techniques and a description of the techniques defined in this document, see Appendix A. For a list of techniques
itemized by ServiceClass, see Appendix B. Numbers assigned to standard techniques are encoded in Appendix C.
Definitions
XieTypAlignment
Alignment defines the valid pixel and scanline alignments allowed for image data transported through the
protocol stream. The server's Alignment attribute is returned by the QueryImageExtension protocol re-
quest.
XieTypAlignment { XieValAlignable, XieValArbitrary }
* Alignable Specifies data units must fit evenly within a byte, or they must fill a byte, or fill a multiple
of bytes (that is, pixels may be 1, 2, 4, 8, 16, 24*, or 32* bits in the protocol stream).
* Arbitrary Specifies data units may fall at any bit address (that is, 10 bit packed pixels are acceptable in
the protocol stream).
* XIE supports pixels up to sixteen (16) bits per band for both SingleBand and TripleBand data. In addition, SingleBand data are
supported up to the depth of the deepest DRAWABLE supported by the server.
XieTypArithmeticOp
ArithmeticOp defines the valid operations for the Arithmetic process element.
XieTypArithmeticOp { XieValAdd,
XieValSub, XieValSubRev,
XieValMul,
XieValDiv, XieValDivRev,
XieValMin, XieValMax,
XieValGamma }
Monadic Dyadic
* Add src1 + constant src1 + src2
* Sub src1 - constant src1 - src2
* SubRev constant - src1 src2 - src1
* Mul src1 * constant
* Div src1 / constant
* DivRev constant / src1
* Min minimum( src1, constant ) minimum( src1, src2 )
* Max maximum( src1, constant ) maximum( src1, src2 )
* Gamma If src1 is Constrained:
(levels - 1) * ((src1 / (levels - 1))constant)
If src1 is Unconstrained:
src1constant
XieTypColorAllocTechnique
ColorAllocTechnique defines the recognized color allocation techniques used by the ConvertToIndex
element.
XieTypColorAllocTechnique { XieValDefault,
XieValColorAlloc_AllocAll,
XieValColorAlloc_Match,
XieValColorAlloc_Requantize }
* Default
ColorAlloc_AllocAll ALLOC-ALL
ColorAlloc_Match MATCH
ColorAlloc_Requantize REQUANTIZE
private-technique-number private-name-string
* The server is required to support the Default technique that is bound to one of the standard techniques defined above or a private tech-
nique.
XieTypColorList
ColorList is the type for the XIE resource used to store COLORMAP allocations made by the ConvertTo-
Index element. A ColorList is a permanent resource and, as such, must be created and destroyed by the
client. A ColorList contains a counted list of the pixel indices that were allocated and the resource-id of
the COLORMAP from which they were allocated.
XieTypColorList XID
XieTypCompareOp
CompareOp defines the operators for the Compare element.
XieTypCompareOp { XieValLT, XieValLE,
XieValEQ, XieValNE,
XieValGT, XieValGE }
* LT src1 < src2 or src1 < constant
* LE src1 £ src2 or src1 £ constant
* EQ src1 = src2 or src1 = constant
* NE src1 ¹ src2 or src1 ¹ constant
* GT src1 > src2 or src1 > constant
* GE src1 ³ src2 or src1 ³ constant
XieTypConstant
Constant is typically used to supply per-band constant values. All constants are passed as floats. When a
constant is to be used as a substitute for a Constrained image pixel, the constant is rounded to the nearest
integer, and then hard-clipped to the range of levels that applies to the pixel for which it is a substitute. In
most other cases the constant is used as is (that is, as a float).
XieTypConstant XieTypTripletofXieTypFloat
Element Op/arg/Tech Type Usage If Constrained ¼
Arithmetic Add Constant Pixel value when monadic round/hard-clip
Sub Constant Pixel value when monadic round/hard-clip
SubRev Constant Pixel value when monadic round/hard-clip
Min Constant Pixel value when monadic round/hard-clip
Max Constant Pixel value when monadic round/hard-clip
Mul Constant Multiplicand Use as is
Div Constant Divisor Use as is
DivRev Constant Dividend Use as is
Gamma Constant Exponent Use as is
BandExtract coefficients Constant Multipliers Use as is
bias Float Final offset Use as is
Blend constant Constant Pixel value when monadic round/hard-clip
alpha-constant Float Constant alpha value Use as is
Compare constant Constant Pixel value when monadic round/hard-clip
Constrain ClipScale Constant Scale src levels to dst levels Use as is
Convert From/To RGB CIElab Matrix Conversion matrix Use as is
CIElabShift Constant White-point Use as is
CIEXYZ Matrix Conversion matrix Use as is
YCbCr Constant Luma values and bias Use as is
YCC Constant Luma values Use as is
YCC Float Scale Use as is
ConvertToIndex Match Float Match-limit, gray-limit Use as is
Convolve kernel LISTofFloat Convolution kernel Use as is
Constant Constant Edge pixel value round/hard-clip
Geometry a,b,c,d,tx,ty Float Coefficients [6] Use as is
constant Constant Fill pixel value round/hard-clip
Gaussian Float Sigma, normalize Use as is
Logical constant Constant Pixel value when monadic round/hard-clip
MatchHistogram Gaussian Float Mean, sigma Use as is
Hyperbolic Float Constant Use as is
PasteUp constant Constant Fill pixel value round/hard-clip
Table 3-2 Treatment of floating point parameters passed through the protocol
XieTypConstrainTechnique
ConstrainTechnique defines various methods of constraining data. These techniques are applied by the
Constrain element.
XieTypConstrainTechnique { XieValConstrain_ClipScale,
XieValConstrain_HardClip }
Constrain_ClipScale CLIP-SCALE
Constrain_HardClip HARD-CLIP
private-technique-number private-name-string
XieTypConvertFromRGBTechnique
ConvertFromRGBTechnique defines the trichromatic colorspaces known to the ConvertFromRGB
element.
XieTypConvertFromRGBTechnique { XieValConvertFromRGB_CIELab,
XieValConvertFromRGB_CIEXYZ,
XieValConvertFromRGB_YCbCr,
XieValConvertFromRGB_YCC }
ConvertFromRGB_CIELab CIELAB
ConvertFromRGB_CIEXYZ CIEXYZ
ConvertFromRGB_YCbCr YCbCr
ConvertFromRGB_YCC YCC
private-technique-number private-name-string
XieTypConvertToRGBTechnique
ConvertToRGBTechnque defines the trichromatic colorspaces known to the ConvertToRGB element.
XieTypConvertToRGBTechnique { XieValConvertToRGB_CIELab,
XieValConvertToRGB_CIEXYZ,
XieValConvertToRGB_YCbCr,
XieValConvertToRGB_YCC }
ConvertToRGB_CIELab CIELAB
ConvertToRGB_CIEXYZ CIEXYZ
ConvertToRGB_YCbCr YCbCr
ConvertToRGB_YCC YCC
private-technique-number private-name-string
XieTypConvolveTechnique
ConvolveTechnique provides various methods of handling edge conditions in the Convolve element.
This technique determines what pixel values are used when Convolve requires data beyond the image
bounds.
XieTypConvolveTechnique { XieValDefault,
XieValConvolve_Constant,
XieValConvolve_Replicate }
* Default
Convolve_Constant CONSTANT
Convolve_Replicate REPLICATE
private-technique-number private-name-string
* The server is required to support the Default technique that is bound to one of the standard techniques defined above or a private tech-
nique.
XieTypDataClass
DataClass defines the class of data being transported over the wire.
XieTypDataClass { XieValSingleBand,
XieValTripleBand }
* SingleBand Specifies index data (for example, ZPixmap format COLORMAP indices) or
achromatic data (bitonal or gray-scale).
* TripleBand Specifies nonindex trichromatic data (RGB or other supported colorspaces).
XieTypDataStream
DataStream is a segmented stream of data units that are transported in either direction through the proto-
col stream. Segments of image data are transported as an arbitrary number of unsigned bytes, whereas all
other types of data (for example, lookup table entries, rectangles, histogram counts, and so on) must be
transported as one or more complete aggregates. The status, indicating the eventual end of data, is sup-
plied in the associated protocol request or reply. The interpretation of the data stream is determined by
parameters specified to the PhotoElement accepting or generating the data.
XieTypDataStream LISTofCARD8
XieTypDataType
DataType defines the limits and processing model for the data.
XieTypDataType { XieValConstrained,
XieValUnconstrained }
* Constrained Specifies pixels are integer values and are limited to the range [0, levels-1].
* Unconstrained Specifies pixels may be any arbitrary value.
XieTypDecodeTechnique
DecodeTechnique defines the techniques that can be used to interpret uncompressed image data or decode
compressed images.
XieTypDecodeTechnique { XieValDecode_UncompressedSingle,
XieValDecode_UncompressedTriple,
XieValDecode_CCITT-G31D,
XieValDecode_CCITT-G32D,
XieValDecode_CCITT-G42D,
XieValDecode_JPEG-Baseline,
XieValDecode_JPEG-Lossless,
XieValDecode_TIFF-2,
XieValDecode_TIFF-PackBits }
Decode_UncompressedSingle UNCOMPRESSED-SINGLE
Decode_UncompressedTriple UNCOMPRESSED-TRIPLE
Decode_CCITT-G31D CCITT-G31D
Decode_CCITT-G32D CCITT-G32D
Decode_CCITT-G42D CCITT-G42D
Decode_JPEG-Baseline JPEG-BASELINE
Decode_JPEG-Lossless JPEG-LOSSLESS
Decode_TIFF-2 TIFF-2
Decode_TIFF-PackBits TIFF-PACKBITS
private-technique-number private-name-string
XieTypDitherTechnique
DitherTechnique defines the techniques that can be used to dither an image.
XieTypDitherTechnique { XieValDefault,
XieValDither_ErrorDiffusion,
XieValDither_Ordered }
* Default
Dither_ErrorDiffusion ERROR-DIFFUSION
Dither_Ordered ORDERED
private-technique-number private-name-string
* The server is required to support the Default technique that is bound to one of the standard techniques defined above or a private tech-
nique.
XieTypEncodeTechnique
EncodeTechnique defines the techniques that can be used to compress an image or format it as uncom-
pressed data.
XieTypEncodeTechnique { XieValEncode_ServerChoice,
XieValEncode_UncompressedSingle,
XieValEncode_UncompressedTriple,
XieValEncode_CCITT-G31D,
XieValEncode_CCITT-G32D,
XieValEncode_CCITT-G42D,
XieValEncode_JPEG-Baseline,
XieValEncode_JPEG-Lossless,
XieValEncode_TIFF-2,
XieValEncode_TIFF-PackBits }
Encode_ServerChoice (not returned by QueryTechniques)
Encode_UncompressedSingle UNCOMPRESSED-SINGLE
Encode_UncompressedTriple UNCOMPRESSED-TRIPLE
Encode_CCITT-G31D CCITT-G31D
Encode_CCITT-G32D CCITT-G32D
Encode_CCITT-G42D CCITT-G42D
Encode_JPEG-Baseline JPEG-BASELINE
Encode_JPEG-Lossless JPEG-LOSSLESS
Encode_TIFF-2 TIFF-2
Encode_TIFF-PackBits TIFF-PACKBITS
private-technique-number private-name-string
XieTypExecutable
Executable is the type used to identify a specific Photoflo instance.
XieTypExecutable
[ name-space ServerIDSpace or XieTypPhotospace
flo-id XieTypPhotoflo or CARD32
]
Name-space identifies the execution domain used for a Photoflo. Flo-id identifies a particular instance of
a Photoflo.
For stored Photoflos name-space is always ServerIDSpace (the value zero) and flo-id is the Photo-
flo's resource-id.
For immediate Photoflos name-space is a Photospace resource-id and flo-id is a 32-bit value that
uniquely identifies the instance of the Photoflo within name-space.
XieTypExportNotify
ExportNotify is used by ExportClient elements to control how ExportAvailable events are sent to
the client.
XieTypExportNotify { XieValDisable
XieValFirstData
XieValNewData }
* Disable Specifies no events are sent.
* FirstData Specifies a single event is sent when the first data is available.
* NewData Specifies an event is sent each time the amount of available data changes from zero to nonz-
ero.
The end of data is signaled by a final flag in the GetClientData reply that is returned when the last segment of data is retrieved.
XieTypExportState
ExportState is a status value returned from an ExportClient element in a reply to the corresponding
GetClientData protocol request.
XieTypExportState { XieValExportDone,
XieValExportMore,
XieValExportEmpty,
XieValExportError }
* ExportDone Specifies all data has been retrieved.
* ExportMore Specifies more data currently is available.
* ExportEmpty Specifies no more data is available at this time.
* ExportError Specifies an error condition prevents data availability.
XieTypFloat
Float specifies data is in the IEEE single-precision format as described in ANSI/IEEE Standard 754-
1985, IEEE Standard for Binary Floating-Point Arithmetic. Float is used only for constant parameter
values, matrix coefficients, and so on but never for transported image data. The byte order of each Float
is dealt with in the same manner as other numeric values; it is determined at core protocol connection
setup time.
XieTypGamutTechnique
GamutTechnique defines the gamut compression techniques used by ConvertToRGB to deal with con-
verted colors that lie outside the gamut of the RGB space.
XieTypGamutTechnique { XieValDefault,
XieValGamut_None,
XieValGamut_ClipRGB }
* Default
Gamut_None NONE
Gamut_ClipRGB CLIP-RGB
private-technique-number private-name-string
* The server is required to support the Default technique that is bound to one of the standard techniques defined above or a private tech-
nique.
XieTypGeometryTechnique
GeometryTechnique defines the retrospective image resampling techniques used by the Geometry ele-
ment.
XieTypGeometryTechnique { XieValDefault,
XieValGeometry_Antialias,
XieValGeometry_AntialiasByArea,
XieValGeometry_AntialiasByLowpass,
XieValGeometry_BilinearInterpolation,
XieValGeometry_Gaussian,
XieValGeometry_NearestNeighbor }
* Default
Geometry_Antialias ANTIALIAS
Geometry_AntialiasByArea ANTIALIAS-BY-AREA
Geometry_AntialiasByLowpass ANTIALIAS-BY-LOWPASS
Geometry_BilinearInterpolation BILINEAR-INTERPOLATION
Geometry_Gaussian GAUSSIAN
Geometry_NearestNeighbor NEAREST-NEIGHBOR
private-technique-number private-name-string
* The server is required to support the Default technique that is bound to one of the standard techniques defined above or a private tech-
nique.
XieTypHistogramData
HistogramData defines the organization of histogram entries created by the ExportClientHistogram
element.
XieTypHistogramData
[ value CARD32
count CARD32
]
XieTypHistogramShape
HistogramShape defines the various match-histogram shape techniques that can be requested in the
MatchHistogram element.
XieTypHistogramShape { XieValHistogram_Flat,
XieValHistogram_Gaussian,
XieValHistogram_Hyperbolic }
Histogram_Flat FLAT
Histogram_Gaussian GAUSSIAN
Histogram_Hyperbolic HYPERBOLIC
private-technique-number private-name-string
XieTypInterleave
Interleave defines the way in which bands of TripleBand data may be interleaved.
XieTypInterleave { XieValBandByPixel,
XieValBandByPlane }
* BandByPixel Specifies the data for all bands are interleaved on a per-pixel basis and transmitted as a sin-
gle data plane (for example, for RGB data red, green, and blue values for a given pixel are
immediately followed by the red, green, and blue values for the next pixel). BandByPixel is
similar to the core protocol ZPixmap format.
* BandByPlane Specifies the data for each band are transmitted as separate data planes (for example, for
RGB data all red data are transmitted in one plane, all green data in a separate plane, and all
blue data in another plane).
Interleave is generally used in conjunction with Orientation, which would define the order of the interleaved bands.
XieTypLevels
Levels describes the potential dynamic range for the quantization levels associated with each band of an
image.
XieTypLevels XieTypTripletofCARD32
Note: for Constrained image data a value of zero (0) represents 232 (4,294,967,296) levels.
XieTypLUT
LUT is the type for the XIE server resource used to hold arrays that map one set of values to another. The
arrays are one-dimensional, and the resource holds either one or three arrays. The ImportClientLUT and
ImportLUT elements are used to import LUT data into a Photoflo, the Point element uses the data, the
ExportLUT element is used to (re)populate the LUT resource, and the ExportClientLUT element is pro-
vided to facilitate sending the LUT data back to the client.
XieTypLUT XID
XieTypMathOp
MathOp defines the valid mathematical operations that can be invoked through the Math element. The
MathOp is applied to each input pixel value to determine the output pixel value.
XieTypMathOp { XieValExp, XieValLn,
XieValLog2, XieValLog10,
XieValSquare, XieValSqrt }
* Exp Exponential
* Ln Natural logarithm
* Log2 Logarithm base 2
* Log10 Logarithm base 10
* Square Square
* Sqrt Square root
XieTypMatrix
Matrix is a 3 x 3 matrix of floats that is used by some of the colorspace conversion techniques (for exam-
ple, conversion between RGB and CIE colorspaces).
XieTypMatrix XieTypTripletofXieTypConstant
XieTypOrientation
Orientation defines the transmission order of image data units through the protocol stream.
XieTypOrientation { XieValLSFirst, XieValMSFirst }
Note: in the examples that follow, the order of bytes in the DataStream should be read from left to right.
encoded-order Specifies the order of bits within bytes of encoded (compressed) data.
Example: Showing 2 bytes (within each byte the first encoded bit is 0, last is bit 7)
LSFirst
MSFirst
76543210 76543210
01234567 01234567
fill-order When multiple pixels are put in the same byte, or a pixel spans multiple bytes, fill-
order specifies whether the pixels (or parts of a pixel) are packed into the most or least
significant bits of a byte first.
Example: Showing 8 2-bit pixels (aa, bb, cc, and so on), and 2 10-bit pixels: aaaaaaaaaa and
bbbbbbbbbb)
LSFirst
MSFirst
ddccbbaa hhggffee
aabbccdd eeffgghh
aaaaaaaa bbbbbbaa xxxxbbbb
aaaaaaaa aabbbbbb bbbbxxxx
pixel-order For pixels that span a byte boundary, pixel-order specifies whether the most or least
significant bits of the pixel are put into the DataStream first. Any pad bits that are
present between pixels always follow the pixel data (that is, pad bits are not considered
to be either LS-bits or MS-bits of the pixel data).
Example: Showing 2 10-bit pixels, each with 2 bits of pad (within each pixel the LS-bits are 0 and
a, the MS-bits are 9 and j, the pad bits are p)
fill-order
LSFirst (pixel-order)
MSFirst (pixel-order)
LSFirst
76543210 dcbapp98 ppjihgfe
98765432 jihgpp10 ppfedcba
MSFirst
76543210 98ppdcba jihgfepp
98765432 10ppjihg fedcbapp
band-order Definition: at the protocol level, the least significant band of trichromatic data is the
first band mentioned in the common name of the colorspace (for example, red is the
least significant band of RGB data).
For BandByPixel data, band-order specifies whether this band is put in the least or
most significant bits of a pixel.
LSFirst
MSFirst
B1B0G2G1G0R2R1R0
R2R1R0G2G1G0B1B0
For BandByPlane data, band-order specifies whether this band corresponds with the
least significant or most significant image plane. Each plane is transported as a sepa-
rate DataStream.
band
LSFirst
MSFirst
0
R7R6R5R4R3R2R1R0
B7B6B5B4B3B2B1B0
1
G7G6G5G4G3G2G1G0
G7G6G5G4G3G2G1G0
2
B7B6B5B4B3B2B1B0
R7R6R5R4R3R2R1R0
For all other instances where a triplet of per-band information is conveyed through the
protocol (levels, constants, and so on), the first element of the triplet corresponds with
the least significant band as defined above.
XieTypPhotoElement
PhotoElement, or just element, is a generic type used for import, process, or export elements in a Pho-
toflo. The syntax of a generic element was described in Chapter 2. The actual element definitions are
found in Chapters 6, 7, and 8.
XieTypPhotoflo
Photoflo is the type for the XIE server resource that is used to represent a sequence of image processing
operations. Stored Photoflos are permanent resources. As such, they must be created and destroyed by
the client.
XieTypPhotoflo XID
For immediate Photoflos, see type Photospace and the ExecuteImmediate protocol request.
XieTypPhotofloOutcome
PhotofloOutcome is returned by the PhotofloDone event and indicates the reason why the Photoflo left
the Active state.
XieTypPhotofloOutcome { XieValFloSuccess,
XieValFloError,
XieValFloAbort }
* FloSuccess Specifies the Photoflo completed normally.
* FloError Specifies the Photoflo terminated due to an error condition.
* FloAbort Specifies the Photoflo was aborted by the client.
XieTypPhotofloState
PhotofloState identifies the current execution state of a Photoflo.
XieTypPhotofloState { XieValInactive,
XieValActive,
XieValNonexistent }
* Inactive Specifies the state of a stored Photoflo prior to execution, after an error or abort, or after
execution completes. Inactive stored Photoflos can be modified and redefined.
* Active Specifies the state of a stored or immediate Photoflo during execution.
Specifies a Photoflo remains Active until:
All export elements have finished their task, and
All data exported for the client have been retrieved, or
An error prevents further progress, or
The client issues an abort request
* Nonexistent Specifies the state of a Photoflo that does not exist (never existed or has been destroyed).
XieTypPhotomap
Photomap is the type for the XIE resource used to store image data in the server. A Photomap is a per-
manent resource that can be created and destroyed by the client. ImportPhotomap is used to import per-
manent image data into a Photoflo. ExportPhotomap is used to (re)populate the resource.
XieTypPhotomap XID
XieTypPhotospace
Photospace is the type for the XIE resource used to define a XIE name space within which immediate
Photoflos may be executed. A Photospace is a permanent resource and as such must be created and de-
stroyed by the client.
XieTypPhotospace XID
XieTypPhototag
Phototag is the position or index of a PhotoElement within a list of elements used to specify a Photoflo.
The first element in the list has a Phototag value of one (1). A Phototag value of zero (0) is reserved for
special purposes, such as, indicating an optional element input that is not connected or indicating Photo-
flo errors that are not specific to an element.
XieTypPhototag CARD16
XieTypProcessDomain
ProcessDomain is a substructure inserted in many PhotoElement definitions. It is used to restrict the
element's processing to a subset of the source data pixels. A ProcessDomain can be either a list-of-
rectangles or a control-plane.
XieTypProcessDomain
[ offset-x INT32
offset-y INT32
domain XieTypPhototag
]
Offset-x and offset-y specifies the spatial registration between the element's data source(s) and the
ProcessDomain (that is, offset relative to the origin of the source(s)). Domain is the Phototag of the ele-
ment providing the ProcessDomain data.
If the value zero (0) is specified for domain, processing is not restricted by the processing domain; other-
wise, domain references an element outputting a list-of-rectangles or image data that is used as a control-
plane.
If domain is a list-of-rectangles, processing is restricted to the intersection of the data source(s) and any
rectangle within the list (offset-x and offset-y are added to the x and y of each rectangle).
If domain is a source of Constrained, SingleBand, bi-level image data (that is, a control-plane), process-
ing is restricted to the intersection of the data source(s) and nonzero locations within domain.
ProcessDomain is not supported by DIS but is included in the subset because the Point element takes a
ProcessDomain as a parameter (in this case domain must be zero).
XieTypRectangle
Rectangle describes a rectangle used in XieTypROI.
XieTypRectangle
[ x INT32
y INT32
width CARD32
height CARD32
]
X and y are the coordinates of the upper left hand corner of the rectangle within the ProcessDomain (the
domains x,y offset is also added to these coordinates to position the rectangle relative to the image being
processed). Width and height are the extent of the rectangle.
XieTypROI
ROI (Rectangles-Of-Interest) is the XIE resource used to contain a list-of-rectangles (input for a
ProcessDomain). A ROI resource is a permanent resource and, as such, must be created and destroyed
by the client. ImportClientROI and ImportROI elements are used to import a list-of-rectangles into a
Photoflo, the ExportROI element is used to (re)populate an ROI resource, and the ExportClientROI
element is provided to facilitate sending rectangles back to the client *.
XieTypROI XID
* The list-of-rectangles that can be retrieved by the client need not be identical to the original list that was received from the client, but it
must be logically equivalent.
XieTypServiceClass
ServiceClass defines the recognized image processing service sets supported by this X Image Extension
standard.
XieTypServiceClass { XieValFull, XieValDIS }
* Full Specifies supports the entire XIE protocol as defined in this document.
* DIS Specifies upports the Document Image Subset, a proper subset of Full XIE.
An itemized list of XIE types, techniques, protocol requests, elements, events, and errors that are included in each ServiceClass can be
found in Appendix B.
XieTypTechniqueGroup
TechniqueGroup defines the standard technique group names that can be queried using the QueryTech-
niques protocol request.
XieTypTechniqueGroup { XieValDefault,
XieValAll,
XieValColorAlloc,
XieValConstrain,
XieValConvertFromRGB,
XieValConvertToRGB,
XieValConvolve,
XieValDecode,
XieValDither,
XieValEncode,
XieValGamut,
XieValGeometry,
XieValHistogram,
XieValWhiteAdjust }
* Default Specifies select all default techniques.
* ColorAlloc Specifies select color allocation techniques.
* Constrain Specifies select techniques for constraining data.
* ConvertFromRGB Specifies select colorspace conversion techniques (for conversion from the RGB color-
space).
* ConvertToRGB Specifies elect colorspace conversion techniques (for conversion to the RGB colorspace).
* Convolve Specifies select techniques for handling convolution edge conditions.
* Decode Specifies select image decoding (decompression) techniques.
* Dither Specifies select dithering techniques.
* Encode Specifies select image encoding (compression) techniques.
* Gamut Specifies select colorspace conversion gamut compression techniques.
* Geometry Specifies select geometric sampling techniques.
* Histogram Specifies select match-histogram shapes.
* WhiteAdjust Specifies select colorspace conversion white point adjustment techniques.
If a vendor defined an additional private technique group, it could be discovered by querying for All groups.
XieTypTechniqueRec
TechniqueRec defines the information that is returned for each technique in the reply to a QueryTech-
niques protocol request.
XieTypTechniqueRec
[ needs-parameters BOOL
group XieTypTechniqueGroup
number CARD16
speed CARD8
name STRING8
]
Needs-parameters indicates that a technique requires additional parameters; or if false, the technique ei-
ther takes no parameters or its parameters are optional. Group identifies which group the technique be-
longs to. Number is the numeric identifier assigned to the technique *. Speed represents the server's view
of the speed of this technique relative to the other techniques in the same group (0 is the slowest, and 255
is the fastest). Name is the XIE compliant technique name string.
* Numbers assigned to standard techniques are encoded in Appendix C.
XieTypTile
Tile defines a source data tile for the PasteUp element.
XieTypTile
[ src XieTypPhototag
dst-x INT32
dst-y INT32
]
Src is the Phototag of the element supplying source data. Dst_x, dst_y specify the coordinates where the
tile belongs in the output data.
XieTypTripletoftype
Tripletof is a generic type used to define a fixed sized array of 3 items* of the specified type.
XieTypTripletof [ v0, v1, v2 : (of type) ]
* Tripletof is usually used to describe per-band attributes and parameters. When dealing with SingleBand images, the value zero must
be used for the nonexistent bands.
XieTypWhiteAdjustTechnique
WhiteAdjustTechnique defines the white point adjustment techniques that can be used when converting
to or from the RGB colorspace.
XieTypWhiteAdjustTechnique { XieValDefault,
XieValWhiteAdjust_None,
XieValWhiteAdjust_CIELabShift }
* Default
WhiteAdjust_None NONE
WhiteAdjust_CIELabShift CIELAB-SHIFT
private-technique-number private-name-string
* The server is required to support the Default technique that is bound to one of the standard techniques defined above or a private tech-
nique.
almost blank
Protocol Parameter Types 3-17
4
Resources
Overview
XIE resources are extension server objects created by the client that contain information used by the
extension in carrying out various protocol requests. There are protocol requests to create and destroy
each resource type. Resource identifiers are generated by the client as defined by the core protocol.
All XIE resources are reference counted.
Binding Resources to Photoflos
Each resource that is referenced from a Photoflo is bound to the Photoflo (and its reference count is
incremented) when the Photoflo becomes Active.
ColorList resources
A ColorList is purged of previous allocations when a Photoflo begins execution and is populated
with new allocations (via ConvertToIndex) as the Photoflo proceeds. A ColorList can only be refer-
enced by one Active Photoflo at a time. The ColorList's reference count is decremented when the
Photoflo is no longer Active.
LUT, Photomap, and ROI resources
These XIE resources consist of two parts: one part contains the resource-id; the other part holds at-
tributes and data. Figure 4-1 pictures the first part as a handle and the second part as a bucket. Upon
resource creation only the handle exists. The bucket is created when the Photoflo (referencing the
handle via an ExportResource element) becomes Active. The handle and bucket are joined when
the Photoflo successfully completes. Conceptually each part contains a separate reference count.
Figure 4-1 Creating and populating a new Photomap
In the case of ImportResource elements, the handle and bucket are both bound to the Photoflo
when it first becomes Active (initialization). For ExportResource elements, only the handle is
bound at this time, and a new bucket is created to hold the forthcoming data. This buckets attributes
are derived from the ExportResource element.
If an export handle is already connected to a bucket, the old bucket remains with its handle until suc-
cessful Photoflo completion. Thus, the old bucket is preserved if the Photoflo terminates due to an
error condition or if an Abort request is received from the client.
The new bucket is filled with data as the Photoflo proceeds. When the Photoflo successfully com-
pletes, old buckets can be freed if they have no other references, and the waiting handle is joined to
the new bucket. This is illustrated in figure 4-2.
Figure 4-2 Process image from Photomap a, place result into Photomap b
This model also allows pseudo in-place operations, such as, that illustrated in figure 4-3. Here an im-
age is imported from a Photomap, processed, and then the result is exported back to the same Pho-
tomap. Note that upon completion the old handle is moved to the new bucket, and the old bucket is
destroyed.
irs
Figure 4-3 Process image from Photomap a in-place
Resource destruction
When a destroy request is received the resource-id is immediately disassociated from the resource and
the resource's reference count(s) is(are) decremented. For each reference count that goes to zero, the
associated resources are freed (for example, memory or colors).
Synchronizing resource access
If multiple Photoflos reference the same resource, the client must synchronize access to the resource
(for example, Await completion of the Photoflo writing the resource before beginning execution of a
Photoflo reading from the resource). Core resources can be volatile, requiring the client to maintain
the data integrity of the resource while the Photoflo is active.
Capability Acquisition
QueryImageExtension
XieReqQueryImageExtension
client-major-version: CARD16
client-minor-version: CARD16
*
server-major-version: CARD16
server-minor-version; CARD16
service-class: XieTypServiceClass
alignment: XieTypAlignment
unconstrained-mantissa: CARD16
unconstrained-max-exp: INT32
unconstrained-min-exp: INT32
constrained-levels: LISTofCARD32
Errors: Alloc
Events: none
QueryImageExtension returns information about the XIE server's capabilities. Each client should
use QueryImageExtension to establish version compatibility between client and server prior to
making any other XIE request. If a client fails first to establish the desired version using Query-
ImageExtension, the behavior of other requests is undefined (which generally means that the server
will use the version number of its own choice).
Client-major-version and client-minor-version specify which version of the XIE protocol the client
would like to use. If the client can support multiple versions, the highest version should be given.
The server-major-version and server-minor-version specify the version of the XIE protocol that the
server expects from the client. If the server supports the version requested by the client, this version
number will be returned. If the client has requested a higher version than is supported by the server,
the server's highest version will be returned. Otherwise, if the client has requested a lower version
than is supported by the server, the server's lowest version will be returned. It is the client's responsi-
bility to decide whether or not it can match the servers version of the protocol.
Service-class specifies the ServiceClass supported by the XIE server . Alignment specifies the image
data alignment restrictions of the server (that is, the alignment of pixels and scanlines).
The following parameters convey the approximate range and granularity of Unconstrained data in
the XIE server. For servers that represent Unconstrained data using floating point, unconstrained-
mantissa returns the number of bits in the servers floating point format (including the sign bit). If
the server uses fixed point, unconstrained-mantissa is zero. Unconstrained-max-exp returns the larg-
est value n such that 2n - 1 is representable in the servers Unconstrained data format. Uncon-
strained-min-exp returns the smallest (most negative) value n such that 2n is representable in the
servers Unconstrained data format.
Constrained-levels provides a hint about how the XIE server might process Constrained data most
efficiently. Constrained-levels returns a list of levels that are recommended for Constrained data
by the server. (a value of zero means 232 levels).
Error Cause
Alloc Insufficient resources
Technique Acquisition
QueryTechniques
XieReqQueryTechniques
technique-group: XieTypTechniqueGroup
*
technique-information: ListofXieTypTechniqueRec
Errors: Alloc, Value
Events: none
QueryTechniques returns information about the standard and private techniques that are supported
by the server. The server may be queried for All techniques, all Default techniques, or a group of
techniques that are functionally similar (for example, all Geometry techniques).
Technique-group specifies the group of techniques for which the server is to return information.
Technique-information is a list of TechniqueRec entries that are returned in arbitrary order. Each
entry contains the following information:
needs-parameters If true, indicates that the technique requires additional parameters; if
false, the technique takes no parameters, or it has parameters that
are optional. If parameters are optional, they must be totally omit-
ted, or they must all be supplied.
group Identifies which group the technique belongs to.
number The numeric identifier assigned to the technique (MS bit is zero for
standard techniques or one for private techniques).
speed The server's assessment of the speed of this technique relative to
other techniques in the same group (0 :== slowest, 255 :== fastest).
name The XIE compliant technique name string of the form:
<STANDARD-TECHNIQUE-NAME> or
_<ORGANIZATION-NAME>_<PRIVATE-TECHNIQUE-NAME>
The technique number is supplied to pipeline elements to specify a desired algorithm or technique.
While numbers for standard techniques can be hard-coded (for example, defined in an include file),
numbers for private techniques must be obtained using the QueryTechniques protocol request prior
to their use.
Error Cause
Alloc Insufficient resources
Value Unknown technique-group
A complete description of each technique and its parameters is given in Appendix A. A summary of standard techniques itemized by
service class can be found in Appendix B. Numbers assigned to standard techniques are encoded in Appendix C.
ColorList
CreateColorList
XieReqCreateColorList
color-list: XieTypColorList
Errors: Alloc, IDChoice
Events: none
CreateColorList creates an unpopulated server resource that can be used to store the list of colors
allocated by a ConvertToIndex element. The COLORMAP allocations that are recorded in a Col-
orList belong to the client that executed the Photoflo that populated the resource (this is not neces-
sarily the same client that created the ColorList). A ColorList cannot be the target of more than one
Active Photoflo at a time.
Color-list is the client supplied ColorList identifier to be assigned to this resource.
Color-list is populated (or repopulated) with new COLORMAP allocations via a ConvertToIndex ele-
ment as the Photoflo executes. The contents of color-list may be queried using QueryColorList.
The client may explicitly purge all allocated cells from color-list using PurgeColorList. The client
may cause an implicit deallocation of cells from color-list by making it the target of a Photoflo and
commencing its execution. An implicit purge also takes place if the COLORMAP referenced by color-
list is freed or if the client that owns the cells exits (that is, the client that populated color-list).
Color-list can be destroyed using DestroyColorList.
Error Cause
Alloc Insufficient resources
IDChoice Invalid color-list
DestroyColorList
XieReqDestroyColorList
color-list: XieTypColorList
Errors: ColorList
Events: none
DestroyColorList disassociates the resource-id from color-list and decrements its reference count. If
there are no other references, it frees colors held in color-list and, then, destroys the ColorList iden-
tified by color-list.
Error Cause
ColorList Invalid color-list
PurgeColorList
XieReqPurgeColorList
color-list: XieTypColorList
Errors: Access, ColorList
Events: none
PurgeColorList frees the colors from the ColorList identified by color-list.
Error Cause
Access Attempt to purge colors when color-list is being written by a Photoflo
ColorList Invalid color-list
QueryColorList
XieReqQueryColorList
color-list: XieTypColorList
*
colormap: COLORMAP
colors: LISTofCARD32
Errors: Alloc, ColorList
Events: none
QueryColorList returns a list of colors allocated by a ConvertToIndex element.
Color-list is the ColorList resource to be queried. Colormap is the COLORMAP from which the col-
ors were allocated. Colors is the list of allocated COLORMAP indices. When there are no colors in
color-list, the value zero (0) is returned for colormap, and the list of colors is of length zero.
Error Cause
Alloc Insufficient resources
ColorList Invalid color-list
Notes:
* The COLORMAP was originally supplied by the client as a ConvertToIndex parameter.
* The returned colors are owned by the server and, therefore, should not be freed via core X protocol requests (for example,
FreeColors)
* The allocated colors can be freed by:
Issuing a PurgeColorList or DestroyColorList request
Commencing execution of a Photoflo that targets color-list
Freeing colormap
Shutting down the client that populated color-list
LUT
CreateLUT
XieReqCreateLUT
lut: XieTypLUT
Errors:: Alloc, IDChoice
Events: none
CreateLUT creates a server resource that is used as a lookup table by the Point element. A lookup
table consists of one or three single dimension arrays, each long enough to contain an entry for all
possible pixels values in the image data to which the Point element will be applied.
Lut is the client supplied LUT identifier to be assigned to this resource.
The LUT is populated (or repopulated) with lookup table entries after the successful execution of a
Photoflo containing an ExportLUT element that targets lut. Lookup table data can be imported into
a Photoflo using an ImportLUT element. These data can be used by Point, and they can be exported
to the client with the aid of an ExportClientLUT element.
Lut can be destroyed using DestroyLUT.
Error Cause
Alloc Insufficient resources
IDChoice Invalid lut
A LUT can be populated with a simple ExecuteImmediate( ImportClientLUT, ExportLUT ) Photoflo. PutClientData is then
used to transport the lookup table entries. See ImportClientLUT and Point for further information on LUTs
DestroyLUT
XieReqDestroyLUT
lut: XieTypLUT
Errors: LUT
Events: none
DestroyLUT disassociates the resource-id from lut and decrements its reference count. If there are
no other references, it destroys the LUT identified by lut.
Error Cause
LUT Invalid lut
Photomap
CreatePhotomap
XieReqCreatePhotomap
photomap: XieTypPhotomap
Errors: Alloc, IDChoice
Events: none
Attribute Value
class Undefined (see text)
type Undefined (see text)
width Undefined (see text)
height Undefined (see text)
levels Undefined (see text)
CreatePhotomap creates a server resource that is used to store image data. Photomap data may be
rendered for display or used as input to control or modify the rendition of another image.
Photomap is the client supplied Photomap identifier to be assigned to this resource. Photomap at-
tributes are defined when a Photoflo containing an ExportPhotomap element populates photomap
with data.
The Photomap is populated (or repopulated) with image data after the successful execution of a Pho-
toflo containing an ExportPhotomap element that targets photomap. Photomap data can be im-
ported into a Photoflo for rendition or control purposes using an ImportPhotomap element. It can
also be exported back to the client with the aid of an ExportClientPhoto element. Photomap attrib-
utes can be queried using QueryPhotomap. Photomap can be destroyed using DestroyPhotomap.
Error Cause
Alloc Insufficient resources
IDChoice Invalid photomap
A Photomap can be populated with a simple ExecuteImmediate(ImportClientPhoto, ExportPhotomap) Photoflo. PutClient-
Data is then used to transport the image data. See ImportClientPhoto and ExportPhotomap and their associated techniques for
more information regarding the format of image data.
DestroyPhotomap
XieReqDestroyPhotomap
photomap: XieTypPhotomap
Errors: Photomap
Events: none
DestroyPhotomap disassociates the resource-id from photomap and decrements its reference count.
If there are no other references, it destroys the Photomap identified by photomap.
Error Cause
Photomap Invalid photomap
QueryPhotomap
XieReqQueryPhotomap
photomap: XieTypPhotomap
*
populated: BOOL
data-type: XieTypDataType
data-class: XieTypDataClass
width: XieTypTripletofCARD32
height: XieTypTripletofCARD32
levels: XieTypLevels
decode: XieTypDecodeTechnique
Errors: Alloc, Photomap
Events: none
QueryPhotomap returns the queriable attributes of a Photomap.
Photomap is the Photomap to be queried.
Populated is a Boolean that indicates that photomap has been populated with attributes and data. If
populated is false, all remaining fields contain zeros. Data-type shows whether the number of quan-
tization levels is valid (Constrained) or unknown (Unconstrained). Data-class is the class of image
data (that is, SingleBand or TripleBand). Width and height are the dimensions of the image data in
pixels (per band). Levels is the potential dynamic range or number of quantization levels (per band).
Decode is the DecodeTechnique that will be required to interpret or decompress the data.
If data-type is Unconstrained, the returned values for levels are zeros. If data-class is SingleBand,
width, height, and levels for unused bands are returned as zeros.
Error Cause
FloAlloc Insufficient resources
Photomap Invalid photomap
ROI
CreateROI
XieReqCreateROI
roi: XieTypROI
Errors: Alloc, IDChoice
Events: none
CreateROI creates a server ROI (Rectangles-Of-Interest) resource. A ROI resource may be im-
ported into a Photoflo and used in conjunction with a ProcessDomain specification to restrict proc-
essing to a subset of image data. The ROI, when populated, will contain a list-of-rectangles (of type
Rectangle).
Roi is the client supplied ROI identifier to be assigned to this resource.
The ROI is populated (or re-populated) with a list-of-rectangles after the successful execution of a
Photoflo containing an ExportROI element that targets roi. An ROI resource does not have any
queriable attributes.
ROI data can be imported into a Photoflo using an ImportROI element. This data, which is used
by several of the PhotoElements defined in chapters 7 and 8, can also be exported back to the client
with the aid of an ExportClientROI element.
Roi can be destroyed using DestroyROI.
Error Cause
Alloc Insufficient resources
IDChoice Invalid roi
An ROI can be populated with a simple ExecuteImmediate ( ImportClientROI, ExportROI ) Photoflo. PutClientData is then
used to transport the list-of-rectangles.
If the client uses ExportClientROI to retrieve a list-of-rectangles from the server, the number of rectangles and the content of the
list that is returned may differ from original list that was obtained from the client, but its contents will be logically equivalent.
DestroyROI
XieReqDestroyROI
roi: XieTypROI
Errors: ROI
Events: none
DestroyROI disassociates the resource-id from roi and decrements its reference count. If there are no
other references, it destroys the ROI identified by roi.
Error Cause
ROI Invalid roi
ServiceClasses defined in this document include: Full XIE and DIS.
Resources 4-10
5
Pipelined Processing
What is a Photoflo?
A Photoflo is a directed acyclic graph. Each node has zero or more input connections and zero or one
output connection. A node specifies the source for an input by identifying another upstream node. A
node's output connection can be used as a source for any number of downstream input connections. A
Photoflo is permitted to have taps and multiple final destinations.
The protocol representation of a Photoflo is a list of elements. Because the entire list is sent to the
server as a single protocol request, the total length of the list, including its protocol header, must fit
within a maximum size protocol message (see, maximum-request-length, established by X11 connec-
tion setup).
Each element of the Photoflo is identified by its position in the list. This position, or index, is called a
Phototag. The first element in the list is index one (1). The order of elements in the list does not
have to match the Photoflo topology because there is no implicit coupling of output N to input N+1.
The source for each element's input connections are explicitly specified using the Phototags of up-
stream elements.
There are three types of elements. Import elements bring data into the Photoflo from external re-
sources or the client, have one output connection, and no input connections. Process elements per-
form some operation on the data (for example, convolution), have one or more input connections, and
exactly one output connection. Export elements emit data from the Photoflo to external resources or
to the client, have one input connection, and no output connections. A Photoflo should include at
least one import element and one export element to be useful.
Import
Process
Export
Number of input connections
none
one or more
one
Number of output connections
one
one
none
Figure 5-1 Photoflo element input and output connections
All data external to the Photoflo (internal server data and client data) are accessed through import
and export elements. Therefore, for purposes of Photoflo definition and modification, X and XIE re-
source-ids are considered element parameters rather than element sources or destinations. No element
is permitted to reference a Photoflo for any reason. It is also an error to specify an export element as
an input to any element.
Figure 5-2 illustrates several capabilities of Photoflo construction. An RGB image is imported from
the client. This image is saved in a Photomap for later reuse. The blue band is selected and trans-
lated (to correct registration). This result is exported back to the client. A BandCombine element
associates a single band imported from a Photomap (the red band), with the green band selected from
the initial RGB image, and the reregistered blue band. The combined image is then converted to in-
dex data and exported to a PIXMAP and to a WINDOW. The color allocation results are saved in a
ColorList.
Figure 5-2 Example Photoflo
Two kinds of Photoflos
There are stored Photoflos and immediate Photoflos. Stored Photoflos persist beyond execu-
tion and may be modified or totally redefined prior to subsequent executions. Immediate Photoflos
are ephemeral a single protocol request defines and begins its execution; then, it is automatically
destroyed upon completion. Services common to both types of Photoflos are:
* Event notification
* Error notification
* Put data: send data from the client into a Photoflo
* Get data: return data exported from a Photoflo back to the client
* Query: return information about the Photoflo
* Await: block future client requests until the Photoflo completes
* Abort: terminate Photoflo execution prematurely
Multi-client Photoflos
A stored Photoflo can be executed by a client other than the client that created it. It is also possi-
ble that the Photoflo may reference resources that belong to other clients, and data may be supplied
and retrieved by various clients. The following rules apply when multiple clients are involved in the
execution of a Photoflo:
* Errors that stem from executing Photoflo elements are sent to the client executing the Photoflo.
* Errors that stem from executing client data put or get requests go to the client executing the request.
* Colors recorded in a ColorList resource belong to the client executing the Photoflo.
* PhotofloDone events are sent to the client executing the Photoflo.
* Multiple clients can Await completion of a given Photoflo.
Photoflo States
Stored Photoflos enter the Inactive state upon creation and transition to the Active state when exe-
cution is requested. Immediate Photoflos are both created and made Active by the execute request.
A Photoflo remains Active until all ImportClient elements have received a final flag, all export
elements have finished their task, and all data exported for the client have been retrieved, or an error
prevents further progress, or the client issues an Abort request. After execution stored Photoflos
return to the Inactive state, whereas immediate Photoflos are destroyed (become Nonexistent).
The client may destroy a stored Photoflo at any time.
Stored Photoflo Immediate Photoflo
Figure 5-3 Photoflo states
Flo'ing Data to a Resource
Besides image rendition and display, immediate or stored Photoflos are also used to populate
XIE resources with data and attributes. Some form of processing may be applied to the data, but in
the simplest case, a two element import/export Photoflo is generally sufficient.
Also all types of ephemeral client data may be imported and used directly by a Photoflo, without the
necessity of first storing it in an XIE resource. For example, simple transport of an image
(compressed or uncompressed) to a WINDOW is expected.
Import element Export element purpose
ImportClientPhoto ExportPhotomap Populate a Photomap resource
ImportClientLUT ExportLUT Populate a LUT resource (lookup table)
ImportClientROI ExportROI Populate a ROI resource (list-of-rectangles)
ImportClientPhoto ExportDrawablePlane Display a bitonal image in a WINDOW
ImportClientPhoto ExportDrawable Display a COLORMAP index image in a WINDOW
ImportPhotomap ExportDrawablePlane Copy an existing bitonal image to a PIXMAP
Table 5-1 Examples of two element Photoflo usage
Name space
For requests that only apply to stored Photoflos (Create, Modify, Redefine, Execute, and Destroy),
the Photoflo is identified solely by its resource-id. For all other requests, events, and errors that ref-
erence a Photoflo, the Photoflo is identified using type Executable, which is a tupple identifying the
name-space and flo-id of the Photoflo.
Name-space for stored Photoflos is always ServerIDSpace (the value zero), and flo-id is the
Photoflo's resource-id.
Name-space for immediate Photoflos is a Photospace resource-id, and flo-id is a 32-bit value that
uniquely identifies the instance of this Photoflo.
CreatePhotospace
XieReqCreatePhotospace
name-space: XieTypPhotospace
Errors: Alloc, IDChoice
Events: none
CreatePhotospace defines a name-space in which immediate Photoflos may be executed. Any
client that needs to instantiate immediate Photoflos must create at least one Photospace.
Name-space is the resource-id for a new Photospace that can be used to accommodate immediate
Photoflos instantiated by this client.
Error Cause
Alloc Insufficient resources
IDChoice Invalid name-space
DestroyPhotospace
XieReqDestroyPhotospace
name-space: XieTypPhotospace
Errors: Photospace
Events: none
DestroyPhotospace will destroy a Photospace. Prior to destroying the Photospace, all Photoflos that
are currently Active in the Photospace will be aborted, exported data pending client retrieval will be
freed, and the Photoflos will be destroyed.
Name-space is the Photospace to be destroyed.
Error Cause
Photospace Invalid name-space
Immediate Photoflos
ExecuteImmediate
XieReqExecuteImmediate
instance: XieTypExecutable
notify: BOOL
element-list: LISTofXieTypPhotoElement
Errors: FloAlloc, FloID, FloElement, Flo . . .
Events: PhotofloDone
ExecuteImmediate defines and begins execution of an immediate Photoflo. Execution is asyn-
chronous. The Photoflo is destroyed after execution completes and all data exported for the client
have been retrieved. It is legal to have multiple unique instances of immediate Photoflos (and
stored Photoflos) Active concurrently.
Instance specifies the Photospace/flo-id tupple by which this Photoflo will be identified in other re-
quests, events, or errors. Notify specifies whether a PhotofloDone event should be sent upon comple-
tion. Element-list defines the import, process, and export elements to be executed.
If any clients have blocked themselves during the execution of the Photoflo (see Await), they will be-
come unblocked when photoflo's state changes from Active to Nonexistent. If notify is true, a Photo-
floDone event is also generated by this transition. Finally, this instance is destroyed.
Error Cause
FloAlloc Insufficient resources
FloID Invalid Executable instance
FloElement Invalid element-type(s) in element-list
Flo . . . See element descriptions for errors detected by elements in element-list
See ExecutePhotoflo for a general outline of the execution phases of a Photoflo.
Stored Photoflos
The following requests are used to: create, modify, redefine, execute, and destroy stored Photoflos.
In these requests the Photoflo instance is identified only by its resource-id. However, errors and
events generated due to these requests identify the instance using type Executable (the name-space is
ServerIDSpace and the flo-id is the Photoflo's resource-id).
CreatePhotoflo
XieReqCreatePhotoflo
photoflo: XieTypPhotoflo
element-list: LISTofXieTypPhotoElement
Errors: Alloc, IDChoice, FloAlloc, FloElement, Flo . . .
Events: none
CreatePhotoflo creates a stored Photoflo resource, defines its complete contents, and sets it in the
Inactive state.
Photoflo is a new resource-id by which this Photoflo will be identified in other requests, events, or er-
rors. Element-list defines the import, process, and export elements to be stored for execution.
Although resources and parameters are specified at creation, no action is taken to validate them at
that time. CreatePhotoflo will only store the Photoflo's definition and parameter validation is de-
layed until an execute request is received.
Error Cause
Alloc Insufficient resources for photoflo
IDChoice Invalid photoflo
FloAlloc Insufficient resources for element-list
FloElement Invalid element-type(s) in element-list
Flo . . . See element descriptions for errors detected by elements in element-list
DestroyPhotoflo
XieReqDestroyPhotoflo
photoflo: XieTypPhotoflo
Errors: Photoflo
Events: none
DestroyPhotoflo will destroy a stored Photoflo. If photoflo was Active, it is aborted, and all ex-
ported data that are pending client retrieval are freed prior to destroying photoflo.
Photoflo is the Photoflo to be destroyed.
Error Cause
Photoflo Invalid photoflo
See also Abort, which terminates a Photoflos execution without destroying it.
ExecutePhotoflo
XieReqExecutePhotoflo
photoflo: XieTypPhotoflo
notify: BOOL
Errors: Photoflo, FloAccess, FloAlloc
Events: PhotofloDone
ExecutePhotoflo changes a stored Photoflo to the Active state. Execution is asynchronous. The
Photoflo returns to the Inactive state when execution completes and all data exported for the client
have been retrieved. It is legal to have multiple stored Photoflos (and immediate Photoflos)
Active concurrently.
Photoflo is the Photoflo to be executed. Notify specifies whether a PhotofloDone event should be
sent upon completion.
Conceptually, Photoflo execution is broken into at least three phases :
1. Initialization:
a. The Photoflo state is set Active.
b. Bind external inputs (XIE reference counts are incremented).
c. Imported attributes are propagated downstream.
d. Attributes and element parameter values are validated.
e. Lookup external destinations.
f. Create receptors for data to be exported to XIE resources.2
2. Execution:
a. Data from server resources, if any, is pulled into the Photoflo.
b. Data from the client, if any, is pushed into the Photoflo (PutClientData).
c. Processed data is exported to server resources as required.2
d. Processed data is made available for client retrieval (GetClientData).
3. Completion:
a. Unbind external inputs.
b. Join exported data with associated XIE resources2 and unbind remaining resources.
c. Report any error that occurred.
d. If notify is true, send a PhotofloDone event.
e. If Await has been requested, unblock client execution.
f. The Photoflo state is set Inactive.
If an error occurs during any phase, the client is notified and the Photoflo is terminated. Other
events can be sent by individual elements as specified in their descriptions.
Error Cause
Photoflo Invalid photoflo
FloAccess Attempt to execute photoflo when it is already Active
FloAlloc Insufficient resources
Flo . . . See element descriptions for errors detected by photoflo elements
ModifyPhotoflo
XieReqModifyPhotoflo
photoflo: XieTypPhotoflo
start: XieTypPhototag
element-list: LISTofXieTypPhotoElement
Errors: Photoflo, FloAlloc, FloElement, FloSource, Flo . . .
Events: none
ModifyPhotoflo allows element parameters of a stored Photoflo to be modified.
Photoflo is the Photoflo to be modified. Start specifies the Phototag where element replacement is to
begin. Element-list is a sequential list of elements that will replace existing elements.
ModifyPhotoflo allows parameter modification only. No topological changes are allowed. Elements
cannot be deleted, inserted, or appended.
Error Cause
Photoflo Invalid photoflo
FloAccess Attempt to change photoflo while it is Active
FloAlloc Insufficient resources
FloElement Attempt to change element-type(s) in element-list
Attempt to append additional element(s) to photoflo
FloSource Invalid start
Attempt to change Phototag input connections in element-list
Flo . . . See element descriptions for errors detected by elements in element-list
Multiple ModifyPhotoflo requests can be sent in order to edit individual elements, but, for greater efficiency and particularly when
repetitive modify/execute requests are expected, elements can be grouped such that a single ModifyPhotoflo can perform multiple
element modifications.
RedefinePhotoflo
XieReqRedefinePhotoflo
photoflo: XieTypPhotoflo
element-list: LISTofXieTypPhotoElement
Errors: FloAccess, Photoflo. FloAlloc, FloElement, Flo . . .
Events: none
RedefinePhotoflo allows all elements of a stored Photoflo to be removed and replaced with a new
list. There are no restrictions on changing element types, Phototag sources, or the list's size.
Photoflo is the Photoflo to be redefined. Element-list is a sequential list of elements that will replace
all existing elements.
Error Cause
Photoflo Invalid photoflo
FloAccess Attempt to change photoflo while it is Active
FloAlloc Insufficient resources
FloElement Invalid element-type(s) in element-list
Flo . . . See element descriptions for errors detected by elements in element-list
RedefinePhotoflo may be considered a hint that the new list of elements is in some way similar to those being replaced. Rede-
finePhotoflo can also be used as a means to conserve resource-ids.
Sending Data to the Server
PutClientData
XieReqPutClientData
instance: XieTypExecutable
element: XieTypPhototag
final: BOOL
band-number: CARD8
data: XieTypDataStream
Errors: FloAlloc, FloAccess, FloID, FloElement, FloValue
Events: none
PutClientData sends a stream of data to an Active Photoflo. Because the complete data object may
be larger than can fit in a single protocol request, XIE allows the stream to be segmented; the last
segment is signaled with a final flag.
Instance and element identify the Photoflo and specific ImportClient element to receive the data.
Final specifies that this is the last (or only) segment of data to be sent.
If element is a band oriented element, band-number specifies which client band of data is being sent
(interleave and band-order specified for the ImportClient element or technique determine how
client bands are mapped to server bands).
Data is a counted list of bytes that comprises the data stream. The organization and contents of the
stream must match the parameters given to the ImportClient element or the results are unde-
fined.
An arbitrary amount of image data can be sent per request, whereas for nonimage data one or more
complete aggregates must be sent per request (for example, one or more LUT array entries).
If too many data are sent (for example, too many rectangles, or too many scanlines), the unwanted
data are discarded. It is an error, however, to send too few data prior to signaling final.
Error Cause
FloAlloc Insufficient resources
FloAccess Executable instance not Active
FloID Invalid Executable instance
FloElement Invalid Phototag or element-type specified by element
FloValue Invalid band-number
For nonimage data, data contains a partial aggregate
All types of client data (list-of-rectangles, lookup tables, and images) are transported to the server using PutClientData. Tiled im-
ages can be transported using multiple ImportClientPhoto elements, which in turn feed a PasteUp element.
Retrieving Data from the Server
GetClientData
XieReqGetClientData
instance: XieTypExecutable
element: XieTypPhototag
max-bytes: CARD32
terminate: BOOL
band-number: CARD8
*
new-state: XieTypExportState
data: XieTypDataStream
Errors: FloAlloc, FloAccess, FloID, FloElement, FloValue
Events: none
GetClientData retrieves data from an ExportClient element within an Active Photoflo. Data are
returned in a contiguous read-once byte stream, which can be requested in segments that are limited
in size by the amount the client desires or the amount available. The format of the data depends on
the parameters given to the ExportClient element from which the data are requested.
Instance and element identify the Photoflo and specific ExportClient element from which to re-
trieve data. Max-bytes specifies the maximum number of data bytes that can be sent to the client.
Terminate is a Boolean that can be used to indicate that no more data are wanted after this request has
been satisfied. Band-number specifies which client band is to be retrieved (interleave and band-
order parameters specified for the ExportClient element technique determine how server bands
are mapped to client bands).
New-state indicates the data availability status of the ExportClient element after satisfying the
current request. Data is the counted list of bytes that is returned.
If terminate is true, new-state will be ExportDone (the ExportClient element will discard any
remaining data and stop producing additional data).
If new-state is ExportEmpty and notify (for the ExportClient element) was specified as
NewData, another ExportAvailable event will be sent when additional data become availabile.
If the request is sent to an ExportClient element that either does not have any data, was termi-
nated by a previous GetClientData request, or has already returned all its data (ExportDone sent),
the request will return a zero length data stream.
Image data are always retrieved from the server as a byte stream, whereas nonimage data are always
returned by the server as one or more complete aggregates (that is, max-bytes is effectively rounded
down by the server to the match the nearest aggregate size).
Error Cause
FloAlloc Insufficient resources
FloAccess Executable instance not Active
FloID Invalid Executable instance
FloElement Invalid Phototag or element-type specified by element
FloValue Invalid band-number
Servers are required to buffer a nonzero amount of data per ExportClient element. Beyond that point execution may be sus-
pended until the client retrieves sufficient data.
Terminate may be used to prematurely terminate output from an ExportClient element. If terminate is not used, all data pro-
duced by the ExportClient element must be retrieved before the Photoflo can leave the Active state.
Status
QueryPhotoflo
XieReqQueryPhotoflo
instance: XieTypExecutable
*
state: XieTypPhotofloState
data-expected: LISTofXieTypPhototag
data-available: LISTofXieTypPhototag
Errors: FloAlloc
Events: none
QueryPhotoflo will return the current status of a Photoflo.
Instance identifies the Photoflo that is being queried. State indicates the state of the Photoflo. Data-
expected is a list of ImportClient elements that are expecting data from the protocol stream.
Data-available is a list of ExportClient elements from which data for the protocol stream are
available. Either or both of these lists may be of length zero.
Specifying an unknown or invalid instance will result in a reply state of nonexistent and zero length
data-expected and data-available lists.
Error Cause
FloAlloc Insufficient resources
Synchronization
Await
XieReqAwait
instance: XieTypExecutable
Errors: FloAlloc
Events: none
Await blocks all further requests for this client connection from being honored by the server while the
Photoflo is Active. When the Photoflo transitions from the Active state, blocked requests are allowed
to be processed in the order received.
Instance identifies the Active Photoflo that is to block requests from the client issuing the Await. If
instance is invalid or the Photoflo is not Active no action is taken; it is not an error, and the client is
not blocked.
Error Cause
FloAlloc Insufficient resources
If a Photoflo has no ExportClient elements, the client can call Await. If a Photoflo has exactly one ExportClient ele-
ment, the client can just read bytes or be event-driven. If a Photoflo has multiple ExportClient elements, the client should be
event-driven.
Warning: Calling Await before sending all import data (including a final flag) or before retrieving all export data will block the cli-
ent from sending or retrieving the remaining data. This will also prevent completion of the Photoflo and prevent any and
all protocol requests from this client from being honored. This deadlock can only be broken by another client completing
or aborting the Photoflo (to release the Await) or by breaking the client connection.
Termination
Abort
XieReqAbort
instance: XieTypExecutable
Errors: none
Events: none
Abort will prematurely terminate execution of a Photoflo.
Instance identifies the Photoflo that is to be aborted. Any output from the Photoflo that is pending
client retrieval is freed. If instance is a stored Photoflo it will return to the Inactive state. Imme-
diate Photoflos are destroyed.
If instance is invalid or the Photoflo is not Active no action is taken; it is not an error, and nothing is
destroyed.
Optimization, an additional phase, would be roughly associated with the initialization phase.
For LUT, Photomap, and ROI resources refer to page 4-1 Binding Resources to Photoflos.
Completion is contingent upon all such data being retrieved by the client.
Pipelined Processing 5-1
6
Import Elements
Overview
Element categories
Import elements are used to bring external image data into a Photoflo. Import elements have no Pho-
totag sources and have one output connection. There are two types of import elements:
* ImportResource Elements obtain data from a server resource (DRAWABLE, LUT, Photomap, or ROI).
* ImportClient Elements require data from the client. This data is transported to the server via the PutClient-
Data protocol request.
Multi-source images
Multiple source images (for example, tiled images, multi-client transport, and so on) require a sepa-
rate import element to describe each segment of the image. The composite image can then be assem-
bled using process elements (for example, BandCombine, Blend, and PasteUp).
Events generated
Certain import elements can generate events to notify the client about abnormal behavior. Two such
events are defined:
* DecodeNotify Notifies the client when anomalies are encountered while decoding a compressed image. It can
also be returned if less data are sent than are required to complete an uncompressed image.
* ImportObscured Notifies the client that one or more regions to be imported from a WINDOW are obscured and un-
available from BACKINGSTORE.
Import from Client
ImportClient elements require data from the client. Element parameters fully specify all the at-
tributes of the client data and describe the format or organization the data will have as it is trans-
ported through the protocol stream. Data is sent to the ImportClient element via the PutClient-
Data protocol request after the Photoflo becomes Active.
ImportClientLUT
XieFloImportClientLUT
class: XieTypDataClass
band-order: XieTypOrientation
length: XieTypTripletofCARD32
levels: XieTypLevels
Errors: FloAlloc, FloMatch, FloValue
Events: none
ImportClientLUT accepts lookup table data from the protocol stream. The transport of data through
the protocol stream is accomplished using PutClientData. These data are accepted by the Point, Ex-
portLUT, and ExportClientLUT elements.
Class indicates the number of lookup arrays to expect. Length specifies the number of entries per ar-
ray. Levels is the number of quantization levels represented per array. Band-order declares the order
of TripleBand arrays, or the order in which pixels from a TripleBand image should be combined to
form indices for a SingleBand array .
The length of each array should match the number of source image levels that will be remapped
through the array. When a TripleBand image is to be remapped through a SingleBand array, the
length of the array should match the product of the source image levels of all three bands1. Table 6-1
summarizes the class of output data to expect from Point, based on the class of LUT and the class of
image provided to Point.
Table 6-1 Relationship between LUT class and image class
LUT class
Source image: SingleBand
Source image: TripleBand
SingleBand
( 1 array )
Output image: SingleBand
the single image band is re-mapped
through the single array
Usage examples:
achromatic --> achromatic
achromatic --> index
Output image: SingleBand
pixels from each image band are combined1 and then re-
mapped through the single array
Usage examples:
trichromatic --> index
trichromatic --> achromatic
TripleBand
( 3 arrays )
Output image: TripleBand
the single image band is re-mapped
through each array separately
Usage examples:
achromatic --> false-color
index----------> trichromatic
Output image: TripleBand
each image band is re-mapped through the corresponding
array
Usage examples:
trichromatic --> trichromatic
The size of each array entry is either 1, 2, or 4 bytes; the smallest size into which the output quanti-
zation levels can be stored. When array entries require multiple bytes, the byte order per entry is de-
termined in the same manner as other numeric data: it is the byte orientation established at core X
connection setup time.
Error Cause
FloAlloc Insufficient resources
FloMatch levels is incompatible with the server's depth handling capabilities
FloValue Invalid class or band-order
When the client targets data at ImportClientLUT, one or more complete array entries must be sent per protocol request (see PutCli-
entData).
ImportClientPhoto
XieFloImportClientPhoto
notify: BOOL
class: XieTypDataClass
width: XieTypTripletofCARD32
height: XieTypTripletofCARD32
levels: XieTypLevels
decode: XieTypDecodeTechnique
decode-params: <technique-dependent>
Errors: FloAlloc, FloMatch, FloValue, FloTechnique
Events: DecodeNotify
Attribute Value
class class of imported image
type Constrained
width width of imported image (in pixels)
height height of imported image (in pixels)
levels levels of imported image
ImportClientPhoto accepts image data from the protocol stream. This data may be processed for
display or used as ProcessDomain data. The attributes and organization of the expected data stream
are fully specified by the parameters. The actual transport of image data through the protocol stream
is requested using the PutClientData protocol request.
Notify enables DecodeNotify events to be sent if anomalies are encountered while interpreting the
imported image data (see DecodeNotify and DecodeTechnique descriptions). Class specifies the
DataClass of the data being imported. Width and height are the per-band image dimensions in pix-
els. Levels is the number of quantization levels per band. Decode is the DecodeTechnique that will
be required to decompress the image. Decode-params is the list of additional parameters required by
decode.
Only Constrained data can be sent through the protocol stream; therefore, levels must be valid.
Error Cause
FloAlloc Insufficient resources
FloMatch levels is incompatible with the server's depth handling capabilities
FloValue Invalid width, height, levels (zero)
Invalid class
FloTechnique Invalid decode technique or decode-params
If the imported client data is compressed, ImportClientPhoto is generally responsible for decoding the data prior to forwarding the
data to downstream elements. An exception to this would be when an export element is a direct recipient of the data and the element
desires data that are encoded using the same technique as decode.
If individual bands of TripleBand data have different widths or heights (for example, down-sampled YCbCr data), it is generally the
client's responsibility to make inter-band dimensions match to render the image (for example, use Geometry with appropriate band-
mask and sample technique). The JPEGBaseline technique that is described in Appendix A, includes a Boolean flag that allows an
image that is interleaved BandByPixel to be up-sampled as part of the decode function.
All data and a final indication must be sent for each band before the Photoflo can leave the Active state. The input data are sent by
the client using the PutClientData protocol request. If a subset of client bands are desired, the bands should be imported as individ-
ual SingleBand images.
ImportClientROI
XieFloImportClientROI
rectangles: CARD32
Errors: FloAlloc
Events: none
ImportClientROI accepts a list-of-rectangles from the protocol stream. These data can be used as
input to a ProcessDomain or an ExportROI or ExportClientROI element. The actual transport of
data through the protocol stream is accomplished using the PutClientData protocol request (the
band-number parameter of PutClientData is ignored).
Rectangles specifies the number of rectangles expected.
Each rectangle is described using numeric values (see Rectangle); as such, the byte order of such data
is determined at core protocol connection setup time.
Error Cause
FloAlloc Insufficient resources
When the client targets data at ImportClientROI, one or more complete Rectangles must be sent per protocol request (see PutCli-
entData).
Import from Resource
ImportResource elements obtain data from server resources: core DRAWABLEs, and XIE LUT,
Photomap, and ROI resources.
The attributes and data of XIE resources are bound to ImportResource elements when the Photo-
flo becomes Active. The same resource may also be the target of an ExportResource element in
the same Photoflo. However, the association between the resource's identifier (XID) and the new at-
tributes and data does not occur until the Photoflo successfully completes (that is, leaves the Active
state). (See Binding Resources to Photoflos in Chapter 4.)
ImportDrawable
XieFloImportDrawable
notify: BOOL
drawable: DRAWABLE
src-x: INT16
src-y: INT16
width: CARD16
height: CARD16
fill: CARD32
Errors: FloAlloc, FloDrawable, FloValue
Events: ImportObscured
Attribute Value
class SingleBand
type Constrained
width width
height height
levels 2depth (that is, drawable depth)
ImportDrawable allows access to data existing in a DRAWABLE. This data may be processed for
display or, if drawable is a BITMAP, used as ProcessDomain data.
Notify enables ImportObscured events to be sent if data for one or more regions of a WINDOW are
obscured and unavailable from BACKINGSTORE (see ImportObscured). Drawable is the
DRAWABLE resource supplying the data. Src-x, src-y, width, and height specify the region of data to
be imported from drawable. Fill is the COLORMAP index to use for all regions that are obscured.
Error Cause
FloAlloc Insufficient resources
FloDrawable Invalid drawable
FloValue Invalid region (src-x, src-y, width, height)
The data are imported as ZPixmap format COLORMAP indices (that is, SingleBand index data). Index data are appropriate for
only a few process elements (for example, where a nearest-neighbor technique is used). ConvertFromIndex can be used to convert
index data prior to feeding it to other process elements. Compare can also be used to produce bitonal data from index data.
ImportDrawablePlane
XieFloImportDrawablePlane
notify: BOOL
drawable: DRAWABLE
src-x: INT16
src-y: INT16
width: CARD16
height: CARD16
fill: CARD32
bit-plane: CARD32
Errors: FloAlloc, FloDrawable, FloValue
Events: ImportObscured
Attribute Value
class SingleBand
type Constrained
width width
height height
levels 2
ImportDrawablePlane allows access to a single plane of data existing in a DRAWABLE. This data
may be processed for display or used as ProcessDomain data.
Notify enables ImportObscured events to be sent if data for one or more regions of a WINDOW are
obscured and unavailable from BACKINGSTORE (see ImportObscured). Drawable is the
DRAWABLE resource supplying the data. Src-x, src-y, width, and height specify the region of data to
be imported from drawable. Fill is the value to substitute for all regions that are obscured. Bit-plane
specifies the plane to be imported from drawable.
Bit-plane must have exactly one bit set to one (1), and the value of bit-plane must be less than 2n,
where n is the depth of drawable. This single bit selects the corresponding bit to be extracted from
pixels within drawable.
Error Cause
FloAlloc Insufficient resources
FloDrawable Invalid drawable
FloValue Invalid bit-plane or region (src-x, src-y, width, height)
ImportLUT
XieFloImportLUT
lut: XieTypLUT
Errors: FloAlloc, FloAccess, FloLUT
Events: none
ImportLUT allows access to lookup table data existing in a LUT resource. These data are accepted
by the Point, ExportLUT, and ExportLUT elements.
Lut is the LUT resource supplying the lookup table. Attributes of the lookup table data are inherited
from lut.
Error Cause
FloAlloc Insufficient resources
FloAccess Attempting to import from lut before it has been populated
FloLUT Invalid lut
ImportPhotomap
XieFloImportPhotomap
notify: BOOL
photomap: XieTypPhotomap
Errors: FloAlloc, FloAccess, FloPhotomap
Events: DecodeNotify
Attribute Value
class Same as photomap
type Same as photomap
width Same as photomap
height Same as photomap
levels Same as photomap
ImportPhotomap allows access to image data existing in a Photomap. This data may be processed
for display or used as ProcessDomain data.
Notify enables DecodeNotify events to be sent if anomalies are encountered while decoding com-
pressed data (see DecodeNotify and the DecodeTechnique descriptions). Photomap is the Photomap
resource supplying image data.
Attributes of the source data are inherited from photomap.
Error Cause
FloAlloc Insufficient resources
FloAccess Attempting to import from photomap before it has been populated
FloPhotomap Invalid photomap
If the data imported from photomap are compressed, ImportPhotomap is generally responsible for decoding the data prior to for-
warding the data to downstream elements. An exception to this would be when an export element is a direct recipient of the data and
the data are already encoded using the technique desired by the export element.
If individual bands of TripleBand, BandByPlane data have different widths or heights (for example, down-sampled YCbCr data), it
is generally the client's responsibility to make inter-band dimensions match to render the image (for example, use Geometry with ap-
propriate band-mask and sample technique). If ImportPhotomaps input data are TripleBand, BandByPixel, the dimensions of
the output bands will match even if the encoded input data are down-sampled.
ImportROI
XieFloImportROI
roi: XieTypROI
Errors: FloAlloc, FloAccess, FloROI
Events: none
ImportROI allows access to a list-of-rectangles existing in a ROI resource. This data may be refer-
enced by a ProcessDomain.
Roi is the ROI resource supplying the list-of-rectangles.
Error Cause
FloAlloc Insufficient resources
FloAccess Attempting to import from roi before it has been populated
FloROI Invalid roi
almost blank
For SingleBand LUTs, Point combines TripleBand src pixel values to provide a compact array indexing scheme. The algorithm
is presented in Figure 7-4.
Import Elements 6-9
7
Process Elements
Overview
Process elements have one or more Phototag sources and have one output connection. Each process
element applies a specific operation to image data within an Active Photoflo. Some process elements
perform their operation on a single source of image data (for example, Geometry). Others, operate
on either a pair of image sources or an image and a constant (for example, Logical). BandCombine
associates bands from three SingleBand image sources to form a TripleBand image. PasteUp can
combine multiple images (tiles) to form a composite image.
The ConvertToIndex element can generate an event to notify the client about color allocation results.
A process element will not be involved in the execution of a Photoflo if there is no eventual consumer
of its output (that is, no terminating export element).
Limiting the Process
Processing may be limited to a subset of the bands present and a subset of pixels within the processed
bands. Data falling outside the selection criteria are passed through unaffected by the element's proc-
ess.
Process Selected Bands
Some process elements accept a band-mask to restrict processing to a subset of the source data bands.
Only bands selected by the band-mask are subject to processing. Other bands present in the image are
passed through to the output. For example: a band-mask of 0012 indicates that only the least signifi-
cant band would be processed (see Orientation for a definition of band ordering).
Process Intersecting Pixels
Dyadic process elements can accept a pair of data sources. These sources are spatially registered at
their origins (upper left corners). Their class and type must match, but their dimensions (width and
height) need not match. The dimensions of the output are determined by src-1. Processing is spa-
tially restricted to the intersection of the sources on a per-band basis. Data from src-1 that do not in-
tersect with src-2 are passed through to the output.
Process Selected Pixels
Some process elements accept a processing domain (ProcessDomain) to restrict processing to a subset
of the source data pixels. The processing domain represents either a list-of-rectangles or a bi-level
SingleBand control-plane.
A processing domain contains an x,y coordinate pair to spatially position the overall processing do-
main relative to the origin of the source(s). It also contains a Phototag that references the import or
process element that supplies the processing domain data. The element referenced by the Phototag
may provide the following:
* list-of-rectangles Imported using ImportROI or ImportClientROI. Processing is restricted to the intersection of
the data source(s) and any rectangle within the list.
* control-plane Imported using ImportDrawable, ImportDrawablePlane, ImportPhotomap, or ImportCli-
entPhoto; or the output of an upstream process element (for example, Compare). Processing is
restricted to the intersection of the data source(s) and nonzero locations within the control-plane.
Processing is not restricted if Phototag zero (0) is specified as the process domains data source.
Figure 7-1 Combining two sources using a control plane Logical: Copy
Data Types
In XIE, an image consists of one or three arrays of pixels, each of which is measured in terms of its
width, height, and depth. Each array, which represents a chromatic band of image data, is dimen-
sioned independently. The depth component of each array is expressed in quantization levels or the
potential dynamic range of the pixels. All process elements within XIE are capable of operating on
image data that have a fixed number of quantization levels. These data are said to be Constrained
such that the minimum possible intensity value of a pixel is zero (0), and the maximum possible in-
tensity level is the number of quantization levels minus one.
With the exception of operations that specifically change the number of quantization levels (for ex-
ample, Dither) all other operations that are performed on Constrained data will maintain the levels
attribute from input to output. An operation that computes a negative pixel value will set the result-
ing pixel to zero. Likewise, an operation that computes a pixel value that would exceed the levels at-
tribute of the data will saturate the resulting pixel at its maximum allowable value (that is, levels-1).
This method of constraining image data is equivalent to the HardClip Constrain technique.
For some operations (for example, Arithmetic operations), it is desirable to allow pixel values to
stray beyond their Constrained values. Such data are said to be Unconstrained and may contain
negative values, fractional values, or other values that might be beyond the normal display capabili-
ties of a frame buffer. Performing a sequence of image operations on Unconstrained image data al-
lows the maximum degree of precision to be maintained throughout the process (although there may
be a cost in performance, depending on the server's capabilities). Several XIE process elements are
capable of operating on either Constrained or Unconstrained data. These elements always output the
same DataType as they are fed at their inputs. An exception to this rule is that certain colorspace
conversion techniques can accept either DataType but are only capable of outputting Unconstrained
data.
XIE provides a complementary pair of elements for converting image data between these two proc-
essing styles. The Unconstrain element simply removes the normal levels restrictions from the data.
The Constrain element provides a means of bringing the data back into a Constrained range. A va-
riety of techniques are available for this purpose that allow the pixel values to be level-shifted, scaled,
clipped, rounded, and so on
Process Categories
* Area elements
Convolve Specifies an area of input pixels is involved in producing each output
pixel (controlled by a convolution kernel).
* Format conversion elements
ConvertFromIndex Specifies convert index data to achromatic or trichromatic data.
ConvertFromRGB Specifies convert RGB data to another trichromatic colorspace.
ConvertToIndex Specifies convert achromatic or trichromatic data to index data.
ConvertToRGB Specifies convert non-RGB trichromatic data to RGB data.
* Dyadic elements: process either two images or an image and a constant
Arithmetic Specifies an arithmetic operation is performed between two images or
an image and a constant.
Blend Specifies combine two images or an image and a constant.
Compare Specifies two images or an image and a constant are compared to
generate a Boolean bitmap result.
Logical Specifies perform logical bit-wise operations on an image, between
two images, or between an image and a constant.
* Geometric elements
Geometry Specifies general affine transform (provides crop, mirror, scale, shear,
rotate, translate, and combinations thereof).
PasteUp Specifies an N-input translate operation that reconstructs an image
from various source tiles.
* Point elements
Math Specifies apply a mathematical operation to each pixel.
Point Specifies remap each pixel value through a lookup table.
* Radiometric elements
BandCombine Specifies merge three SingleBand images.
BandExtract Specifies extract SingleBand data from a trichromatic source.
BandSelect Specifies select a single band of data from a trichromatic source.
Constrain Specifies constrain an image to a fixed number of quantization levels.
Dither Specifies reduce image quantization levels through an area technique.
MatchHistogram Specifies transform an image to have a specific histogram shape.
Unconstrain Specifies remove the normal levels restrictions from the image data.
Process Definitions
The complete list of process PhotoElements follows in alphabetical order.
Arithmetic
XieFloArithmetic
src-1: XieTypPhototag
src-2: XieTypPhototag
domain: XieTypProcessDomain
constant: XieTypConstant
operator: XieTypArithmeticOp
band-mask: CARD8
Errors: FloAlloc, FloSource, FloDomain, FloMatch, FloOperator, FloValue
Events: none
Attribute Value
class Same as src-1
type Same as src-1
width Same as src-1
height Same as src-1
levels Same as src-1
Arithmetic produces output data by performing an addition, subtraction, minimum, or maximum op-
eration between two data sources or between a single data source and a constant. Furthermore, multi-
plication, division, or gamma correction may by applied to a single data source.
When two sources are involved, src-1 and src-2 are the Phototags of the elements supplying source
data (constant is ignored). If the operation is to involve a constant, src-1 is one operand, src-2 must be
zero, and constant is used as the other operand. Domain may control the subset of source data that
will be operated upon. Operator is the arithmetic operation to be performed. Band-mask specifies
which bands are to be operated upon.
When two sources are involved, all attributes, other than width and height, must match; all output at-
tributes are inherited from src-1.
Pixel computations that would lead to errors will yield valid server-dependent values (for example,
dividing by a Constrained pixel value of zero might result in a value of levels-1) . Using band-mask
to select source data that have two (2) or less levels is not permitted.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src-1 or src-2
src-2 has been specified with a monadic operator (for example, Div or Gamma)
FloDomain Invalid domain
FloMatch class, type, or levels differs between src-1 and src-2
Selected source data are bitonal (that is, 2 or less levels)
FloOperator Invalid operator
BandCombine
XieFloBandCombine
src-1: XieTypPhototag
src-2: XieTypPhototag
src-3: XieTypPhototag
Errors: FloAlloc, FloSource, FloMatch
Events: none
Attribute Value
class TripleBand
type Same as src-1
width Same as srcs
height Same as srcs
levels Same as srcs
BandCombine merges three SingleBand data sources to produce a TripleBand result.
Src-1, src-2, and src-3 are the Phototags of the elements supplying source data. All three sources
must be of the same type, and each source must be SingleBand. Other attributes that are taken from
the individual sources may differ. The output will be TripleBand.
No subsetting by ProcessDomain is provided.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src-1, src-2, or src-3
FloMatch A source has more than one band
type differs between sources
BandExtract
XieFloBandExtract
src: XieTypPhototag
coefficients: XieTypConstant
bias: XieTypFloat
levels: CARD32
Errors: FloAlloc, FloSource, FloMatch
Events: none
Attribute Value
class SingleBand
type Same as src
width Same as src
height Same as src
levels levels or unknown (see text)
BandExtract produces SingleBand output data from a TripleBand source by multiplying a pixel
value from each source band by its corresponding coefficient and then summing the results with the
bias value.
Src is the Phototag of the element supplying source data. Coefficients is a three (3) element array
that determines the proportion of each source band pixel that is used to form the output. The bias
value is added to each output pixel. Levels is used as the levels attribute of the output data if the src
data are Constrained; otherwise, it is ignored.
The source data must be TripleBand, and all bands must have equal dimensions. The output data will
be SingleBand with levels taken from the levels parameter if type is Constrained. All other attrib-
utes are inherited from src.
No subsetting by ProcessDomain is provided (the entire image is processed).
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloMatch src is not TripleBand
Unequal inter-band dimensions (width or height)
BandExtract can be used to extract a band of luminance data from an RGB image. It can also be used to compute COLORMAP in-
dices in cases where the contents of the COLORMAP is well ordered (for example, a Standard-COLORMAP or a TrueColor
visual).
BandSelect
XieFloBandSelect
src: XieTypPhototag
band-number: CARD8
Errors: FloAlloc, FloSource, FloMatch, FloValue
Events: none
Attribute Value
class SingleBand
type Same as src
width Same as band selected from src
height Same as band selected from src
levels Same as band selected from src
BandSelect produces SingleBand output data by selecting a single band from a TripleBand source.
Src is the Phototag of the element supplying source data. Band-number specifies which src band is to
be selected to provide the output data.
No subsetting by ProcessDomain is provided.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloMatch src is not TripleBand
FloValue Invalid band-number
Blend
XieFloBlend
src-1: XieTypPhototag
src-2: XieTypPhototag
alpha: XieTypPhototag
constant: XieTypConstant
alpha-const: XieTypFloat
domain: XieTypProcessDomain
band-mask: CARD8
Errors: FloAlloc, FloSource, FloDomain, FloMatch, FloValue
Events: none
Attribute Value
class Same as src-1
type Same as src-1
width Same as src-1
height Same as src-1
levels Same as src-1
Blend produces output data from two data sources or a single data source and a constant. Each out-
put pixel is a percentage combination of the source values, as controlled by the alpha input or the al-
pha constant.
When two sources are involved, src-1 and src-2 are the Phototags of the elements supplying source
data (constant is ignored). If the operation is to involve a constant, src-1 is one operand, src-2 must
be zero, and constant is used as the other operand. If alpha is nonzero, it controls the blend propor-
tion for each pixel that is processed; otherwise, alpha-const provides this control. Domain may con-
trol the subset of source data that will be operated upon. Band-mask specifies which bands are to be
operated upon.
When two sources are involved, all attributes, other that width and height, must match. If alpha is
nonzero, it must be a source of Constrained data. Using band-mask to select source data that have
two (2) or less levels is not permitted.
Within the intersection of the source(s) and domain, each output pixel is a blend of the corresponding
pixels from src-1 and src-2 (or src-1 pixels blended with constant). The degree of blend is deter-
mined by the corresponding value taken from alpha or the value of alpha-const. If alpha is nonzero,
the proportion of blend is further scaled by alpha-const:
output = src-1 * (1 - alpha / alpha-const) + src-2 * (alpha / alpha-const)
(where alpha-const is greater than 0.0).
If alpha is zero:
output = src-1 * (1 - alpha-const) + src-2 * alpha-const
(where alpha-const is in the range [0.0, 1.0]).
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src-1, src-2, or alpha
FloDomain Invalid domain
FloMatch Incompatible attributes between src-1 and src-2
alpha is Unconstrained
Selected source data are bitonal (that is, 2 or less levels)
FloValue alpha is zero and alpha-const is outside the range [0.0, 1.0]
alpha is nonzero and alpha-const is zero or negative
Compare
XieFloCompare
src-1: XieTypPhototag
src-2: XieTypPhototag
domain: XieTypProcessDomain
constant: XieTypConstant
operator: XieTypCompareOp
combine: BOOL
band-mask: CARD8
Errors: FloAlloc, FloSource, FloDomain, FloMatch, FloOperator
Events: none
Attribute Value
class See text
type Constrained
width Same as src-1
height Same as src-1
levels 2 per band (see text)
Compare takes two data sources or a single data source and a constant and generates a Boolean bit-
map output that reflects the results of a point-wise comparison. The output data has a value of one
(1) wherever the comparison is true, and a value of zero (0) everywhere else (that is, comparison false
or comparison not performed). Compare may be requested on a per-band basis, or for all bands
taken together.
When two sources are involved, src-1 and src-2 are the Phototags of the elements supplying source
data (constant is ignored). If the operation is to involve a constant, src-1 is one operand, src-2 must be
zero, and constant is used as the other operand. Domain may control the subset of source data that
will be compared. Operator is the logical predicate operator used in the comparison. Combine is a
Boolean that determines if the comparison should be done on a per-band basis or on an all bands ba-
sis. Band-mask specifies which bands are to be involved.
If combine is true or src-1 is SingleBand, the output data will form a single Boolean bitmap. If src-1
is TripleBand and combine is false, the output data will yield three separate Boolean bitmaps (for this
case band-mask must specify all bands).
If src-1 is TripleBand and combine is true, only the EQ and NE operators are allowed; equality is
established for each band selected by band-mask, and then the result is logically ANDed to derive
equality (inequality is a logical NOT of this result). For this case, width and height must match for all
bands selected by band-mask.
combine
input class
band-mask
output class
True
SingleBand
TripleBand
n/a
selected bands
SingleBand
SingleBand
False
SingleBand
TripleBand
n/a
all bands
SingleBand
TripleBand
Table 7-1 Compare parameter and DataClass dependencies
When two sources are involved, all attributes, other than width and height, must match. The com-
parison is performed over the intersect of the source(s) as restricted by domain. All points not com-
pared are given the value zero (0).
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src-1 or src-2
FloDomain Invalid domain
FloOperator Invalid operator
FloMatch Class differs between src-1 and src-2
Invalid combination of operator and combine
TripleBand, and combine is false, and band-mask incomplete
Compare does not support inter-band distance metrics therefore, combined LT, LE, GT, and GE operators are not supported. Cli-
ents may implement these using other elements in concert with Compare.
Typical uses for Compare include: creating data to be used as a control-plane for a ProcessDomain and converting index data into
bitonal image data.
Constrain
XieFloConstrain
src: XieTypPhototag
levels: XieTypLevels
constrain: XieTypConstrainTechnique
constrain-params: <technique-dependent>
Errors:: FloAlloc, FloSource, FloTechnique
Events: none
Attribute Value
class Same as src
type Constrained
width Same as src
height Same as src
levels levels
Constrain applies a quantization model to the image data to convert the data to a fixed number of
quantization levels. Application of the quantization model may involve steps such as range shifting,
scaling, clipping, and rounding.
Src is the Phototag of the element supplying source data. Levels is the number of quantization levels
desired in the output data. Constrain specifies the ConstrainTechnique to be used when constraining
the data. Constrain-params is the list of additional parameters required by constrain.
If the input image is already Constrained the data will be re-Constrained.
No subsetting by band mask or ProcessDomain is provided (the entire image is Constrained).
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloTechnique Invalid constrain technique or constrain-params
ConvertFromIndex
XieFloConvertFromIndex
src: XieTypPhototag
colormap: COLORMAP
class: XieTypDataClass
precision: CARD8
Errors: FloAlloc, FloSource, FloColormap, FloMatch, FloValue
Events: none
Attribute Value
class class
type Constrained
width Same as src
height Same as src
levels 2precision (per band)
ConvertFromIndex converts COLORMAP index data into achromatic or trichromatic data.
Src is the Phototag of the element supplying source data. Colormap is the COLORMAP from which to
obtain the value for each output pixel. Class specifies the DataClass of the desired output data. Pre-
cision specifies how many bits (most significant) are to be used from the red, green, and blue values
found in colormap.
If class is SingleBand and a trichromatic colormap is specified (StaticColor, PseudoColor,
TrueColor, or DirectColor), the gray shade for each pixel is taken from the red values in col-
ormap. If class is TripleBand and an achromatic colormap is specified (StaticGray or Gray-
Scale), the red band will be replicated to populate the green and blue output bands.
The depth of colormap must match the levels attribute of src (that is, 2depth must equal levels).
No subsetting by band mask or ProcessDomain is provided (the entire image is converted).
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloColormap Invalid colormap
FloMatch levels of src do not match depth of colormap
FloValue Invalid class or precision
To achieve predictable results, the client should not modify colormap cells referenced by the source data while the Photoflo is Active
(see Await for synchronization help).
A value of bitsPerRGBValue or less (defined in the VISUAL of colormap) is usually appropriate for precision.
Compare can be used to convert index data into bitonal data. Use ConvertFromIndex followed by BandExtract to convert col-
ored index data into full fidelity achromatic data.
ConvertFromRGB
XieFloConvertFromRGB
src: XieTypPhototag
convert: XieTypConvertFromRGBTechnique
convert-params: <technique-dependent>
Errors:: FloAlloc, FloSource, FloMatch, FloTechnique
Events: none
Attribute Value
class TripleBand
type convert technique dependent
width Same as src
height Same as src
levels convert technique dependent
ConvertFromRGB converts RGB source data to an alternate colorspace.
Src is the Phototag of the element supplying source data (RGB assumed). Convert is the Convert-
FromRGBTechnique that will be used in the conversion to the destination colorspace. Convert-
params is the list of additional parameters required by convert.
In addition to colorspace conversion, some techniques allow for adjusting the white point of the out-
put data (see Appendix A, Convert From RGB Technique, for more information on conversion
techniques).
The source data must be TripleBand, and all bands must have equal dimensions. The type and levels
of the output data are determined by convert technique parameters. All other attributes are inherited
from src.
No subsetting by ProcessDomain is provided (the entire image is processed).
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloMatch src is not TripleBand
Unequal inter-band dimensions (width or height)
FloTechnique Invalid convert or convert-params
ConvertToIndex
XieFloConvertToIndex
notify: BOOL
src: XieTypPhototag
colormap: COLORMAP
color-list: XieTypColorList
color-alloc: XieTypColorAllocTechnique
color-alloc-params: <technique-dependent>
Errors: FloAlloc, FloSource, FloColormap, FloColorList, FloMatch, FloValue
Events: none
Attribute Value
class SingleBand
type Constrained
width Same as src
height Same as src
levels 2depth (that is, colormap depth)
ConvertToIndex allocates and/or matches colors or gray shades, as required, from a COLORMAP. It
produces pixel indices as output data, and records indices that it allocates in a ColorList. The speci-
fied color-alloc technique may generate a ColorAlloc event to warn the client that results are of
lesser fidelity than desired.
Notify allows the client to be notified about inferior results from color allocation or matching. Src is
the Phototag of the element supplying Constrained source data. Colormap is the COLORMAP from
which colors or gray shades are allocated and/or matched. Color-list is the ColorList where allocated
COLORMAP indices are to be stored. Color-alloc specifies the desired ColorAllocTechnique. Color-
alloc-params is the list of additional parameters required by color-alloc.
Color-list is purged of any colors it already contains when Photoflo execution begins. Allocated
COLORMAP indices can be freed using PurgeColorList, DestroyColorList, or by making color-list
the target of an Active Photoflo.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloColormap Invalid colormap
FloColorList Invalid color-list
FloAccess color-list is already being used by another Active Photoflo
FloMatch Unequal inter-band dimensions (width or height) or Unconstrained src data
FloTechnique Invalid color-alloc technique or color-alloc-params
ConvertToIndex is usually a preparatory step for an ExportDrawable element. Alternatively, continuous-tone data can be con-
verted to a fixed palette of COLORMAP index entries using Point. Or BandExtract can be used if the COLORMAP contains a ramp
of colors or gray shades (for example, a Standard-COLORMAP or a TrueColor visual). Bitonal image data can be pre-
sented directly to ExportDrawablePlane, allowing the GCONTEXT mechanism to translate ones and zeros in the image into fore-
ground and background colors in the DRAWABLE.
If colormap is static, image colors or gray shades must be matched to those available in colormap. Because no cells are actually
allocated, color-list can be specified as zero (0). Of the three standard techniques defined in this document only, ColorAlloc_Match
is appropriate for static COLORMAPs. If colormap is dynamic, image colors or gray shades may be matched or allocated from
colormap depending on the color-alloc technique; colormap and the list of cells actually allocated are stored in color-list.
Although the three standard techniques defined in this document allocate read-only cells, ConvertToIndex could be extended with
private techniques that allocate, match, or write into read-write cells.
ConvertToRGB
XieFloConvertToRGB
src: XieTypPhototag
convert: XieTypConvertToRGBTechnique
convert-params: <technique-dependent>
Errors: FloAlloc, FloSource, FloTechnique
Events: none
Attribute Value
class TripleBand
type convert technique dependent
width Same as src
height Same as src
levels convert technique dependent
ConvertToRGB converts alternate colorspace source data into RGB data.
Src is the Phototag of the element supplying source data. Convert is the ConvertFromRGBTech-
nique that will be used in the conversion from the source colorspace. Convert-params is the list of
additional parameters required by convert.
In addition to colorspace conversion, some techniques allow for adjusting the white point of the
source data prior to conversion and compressing the gamut of the output data (see Appendix A,
Convert To RGB Technique, for more information on conversion techniques).
The source data must be TripleBand, and all bands must have equal dimensions. The type and levels
of the output data are determined by convert technique parameters. All other attributes are inherited
from src.
No subsetting by band mask or ProcessDomain is provided (the entire image is converted).
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloMatch src is not TripleBand
Unequal inter-band dimensions (width or height)
FloTechnique Invalid convert or convert-params
Arithmetic or Point can be used to gamma-correct the resulting data prior to displaying it.
Convolve
XieFloConvolve
src: XieTypPhototag
domain: XieTypProcessDomain
kernel: LISTofXieTypFloat
kernel-size: CARD8
band-mask: CARD8
convolve: XieTypConvolveTechnique
convolve-params: <technique-dependent>
Errors: FloAlloc, FloSource, FloDomain, FloMatch, FloValue, FloTechnique
Events: none
Attribute Value
class Same as src
type Same as src
width Same as src
height Same as src
levels same as src
Convolve produces output data by convolving each input pixel value (and surrounding area) with the
specified convolution kernel.
Src is the Phototag of the element supplying source data. Domain may control the subset of the im-
age that will be operated upon. Kernel contains the coefficients used in the convolution process.
Kernel-size specifies the dimension of kernel. Band-mask specifies which bands are to be operated
upon. Convolve specifies the ConvolveTechnique for handling edge conditions (when kernel re-
quires data outside of src). Convolve-params is the list of additional parameters required by con-
volve. Kernel represents a square array of float data that has odd dimensions. Thus, a single dimen-
sion is used to specify, kernel-size.
Using band-mask to select source data that have two (2) or less levels is not permitted.
All output data attributes are inherited from the source data.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloDomain Invalid domain
FloMatch Selected source data are bitonal (that is, 2 or less levels)
FloValue Invalid kernel-size (for example, not odd)
FloTechnique Invalid convolve edge handling technique or convolve-params
For TripleBand data, convolution using the same kernel is permuted over all three bands.
Dither
XieFloDither
src: XieTypPhototag
levels: XieTypLevels
band-mask: CARD8
dither: XieTypDitherTechnique
dither-params: <technique-dependent>
Errors: FloAlloc, FloSource, FloValue, FloMatch, FloTechnique
Events: none
Attribute Value
class Same as src
type Constrained
width Same as src
height same as src
levels levels
Dither is used to reduce the number of quantization levels in an image. It accomplishes this by af-
fecting adjacent pixels (area affect) to make up for the lack of depth resolution.
Src is the Phototag of the element supplying source data. Levels is the number of levels desired in
the output data. Band-mask specifies which bands are to be operated upon. Dither specifies the de-
sired DitherTechnique. Dither-params is the list of additional parameters required by dither.
The source data must be Constrained. Using band-mask to select source data that have two (2) or
less levels is not permitted.
No subsetting by band mask or ProcessDomain is provided (the entire image is processed).
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloMatch Unconstrained src data
Selected source data are bitonal (that is, 2 or less levels)
FloValue Invalid output levels: less than two, or greater than src levels
FloTechnique Invalid dither technique or dither-params
Geometry
XieFloGeometry
src: XieTypPhototag
width: CARD32
height: CARD32
coefficients: XieTypFloat[6]
constant: XieTypConstant
band-mask: CARD8
sample: XieTypGeometryTechnique
sample-params: <technique-dependent>
Errors: FloAlloc, FloSource, FloValue, FloTechnique
Events: none
Attribute Value
class Same as src
type Same as src
width width
height height
levels Same as src
Geometry is used to perform geometric transformations on image data. Linear geometric resampling
operations are implemented, such as, crop, mirror, scale, shear, rotate, translate, and combinations
thereof.
Src is the Phototag of the element supplying source data. Width and height specify the dimensions of
the output data. Coefficients is a list of values (a,b,c,d,tx,ty) that control the geometric transforma-
tion. Constant is a fill value used for output pixels that do not map back to a src pixel. Band-mask
specifies which bands are to be operated upon. Sample is the GeometryTechnique to be used for ret-
rospectively resampling src. Sample-params is the list of additional parameters required by sample.
Figure 7-2 shows a combined crop and scale for a src with dimensions w and h, and output width w
and height h. The mapping between the coordinate systems is specified from output back to src; that
is, for each output pixel (x,y), the coordinate location (x,y) at which to sample src is given by:
Geometry can be visualized as stepping through each possible output pixel location in turn and com-
puting the location from which to obtain each input pixel value. Often a given output pixel location
(x,y) will not correspond exactly to a single pixel in the input image. The sample technique is
used to determine how the input data will be interpolated to produce each output pixel value.
Figure 7-2 A sample geometric transform: crop and scale
The region to be cropped in the input image is implicitly defined by the dimensions of the output im-
age and the mapping from output to input coordinates. Depending on the size of the input and output
images, the amount of scaling specified, and the amount of translation in the mapping, the shadow
of the output image may extend beyond the boundaries of the input image, as in Figure 7-3. Pixels in
the output image that map off the edge of the input image will be assigned the constant value.
Figure 7-3 Background fill used for pixels beyond the edge
Transformation Coefficients
The coordinate mapping (a,b,c,d,tx,ty), together with the output width and height, fully specify the
geometric transformation. To aid in computing the desired transform, one might:
* Draw a picture of the input and output images. Label the corners of the output image A,B,C,D. They will have coordinates
x,y at (0,0), (width-1,0), (0,height-1), and (width-1,height-1),
* Next compute or deduce the coordinates (x,y) of A,B,C,D in the input coordinate space,
* For three corners (preferably those with a 0 for either x or y), write down the basic mapping equation with known (x,y)
and (x,y) specified. Each corner will give two equations, and simultaneously solving the six equations for the three corners
will allow (a,b,c,d,tx,ty) to be deduced. The remaining corner may be used to check that these parameters have been derived
correctly.
The following briefly (and approximately) summarizes the intuitive role of each parameter:
a,d Scaling parameters. Increasing a and d will make the output image appear smaller, whereas
decreasing them will make the output pixels appear larger.
b,c Rotation/skew parameters. If b and c are zero, the output image will be a rectangular scal-
ing of the input image. If a and d are both zero, b is one and c is negative one, the image
will appear rotated. The magnitude of b and c will affect scaling as well, if a and d are
zero. If more than two of (a,b,c,d) are nonzero, the effect is complicated. The image may
appear skewed and scaled.
tx,ty Translation parameters. Used to specify the offset between input and output coordinate sys-
tems.
width,height These specify the output image dimensions of the selected band(s). Note that increasing the
output image height and width over the input image size will not by itself cause magnifica-
tion ¾ if a and d are one (1) and b and c are zero (0), the output image will have the same
appearance as the input, except that the borders will shrink or expand (as determined by
width and height) and new areas of the image will be filled with constant.
Trichromatic image bands can be operate individually, all together or in any combination using band-
mask. Because applying the same (a,b,c,d,tx,ty) mapping to inputs with diverse sizes will specify
different transformations, operating on all bands in unison (band-mask of 1112) is most appropriate if
the dimensions of all bands are equal. No subsetting by ProcessDomain is provided (selected bands
are processed in their entirety).
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloValue Invalid coefficients, width, or height
FloTechnique Invalid sample technique or sample-params
Logical
XieFloLogical
src-1: XieTypPhototag
src-2: XieTypPhototag
domain: XieTypProcessDomain
constant: XieTypConstant
operator: GCfunction*
band-mask: CARD8
Errors: FloAlloc, FloSource, FloDomain, FloMatch, FloOperator, FloValue
Events: none
Attribute Value
class Same as src-1
type Constrained
width Same as src-1
height Same as src-1
levels Same as src-1
Logical performs per-pixel bit-wise operations on a single data source, or between two data sources,
or between a single data source and a constant.
When two sources are involved, src-1 and src-2 are the Phototags of the elements supplying source
data (constant is ignored). If the operation is to involve a constant, src-1 is one operand, src-2 must be
zero, and constant is used as the other operand. Domain may control the subset of source data that
will be operated upon. Operator is the logical operator to be used. Band-mask specifies which bands
are to be operated upon.
The value of operator matches the GC-function values defined by the core protocol specification
for CreateGC. The output of Logical is determined by the number of data sources and operator:
GC-function1 monadic operation dyadic operation
Clear 0 0
And constant AND src-1 src-2 AND src-1
AndReverse constant AND (NOT src-1) src-2 AND (NOT src-1)
Copy constant src-2
AndInverted (NOT constant) AND src-1 (NOT src-2) AND src-1
NoOp src-1 src-1
Xor constant XOR src-1 src-2 XOR src-1
Or constant OR src-1 src-2 OR src-1
Nor (NOT constant) AND (NOT src-1) (NOT src-2) AND (NOT src-1)
Equiv (NOT constant) XOR src-1 (NOT src-2) XOR src-1
Invert NOT src-1 NOT src-1
OrReverse constant OR (NOT src-1) src-2 OR (NOT src-1)
CopyInverted NOT constant NOT src-2
OrInverted (NOT constant) OR src-1 (NOT src-2) OR src-1
Nand (NOT constant) OR (NOT src-1) (NOT src-2) OR (NOT src-1)
Set 1 1
When two sources are involved, all attributes, other than width and height, must match. All source
data must be Constrained, and levels must be a power of two. Output attributes are inherited from
src-1.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src-1 or src-2
FloDomain Invalid domain
FloOperator Invalid operator
FloMatch src-1 or src-2 is not Constrained
levels or class differs between src-1 and src-2
levels is not a power of 2
MatchHistogram
XieFloMatchHistogram
src: XieTypPhototag
domain: XieTypProcessDomain
shape: XieTypHistogramShape
tech-params: <technique-dependent>
Errors: FloSource, FloDomain, FloAlloc, FloMatch, FloTechnique
Events: none
Attribute Value
class SingleBand
type Constrained
width Same as src
height Same as src
levels Same as src
MatchHistogram produces output data that differs from the source data in terms of its pixel value
distribution or histogram. It allows the client to specify the desired state of the resulting data's histo-
gram (algorithmic description of resulting histogram shape).
Src is the Phototag of the element supplying source data. Domain may control the subset of the
source data to operated upon. Shape is a HistogramShape that specifies the form of the desired out-
put data histogram. Shape-params is the list of additional parameters required by shape.
The source data must be Constrained and SingleBand, and it must have three (3) or more levels.
When a ProcessDomain is used, only data that intersects with domain is included in the histogram,
and only that data will be affected in the result of the histogram matching operation (all other data
will pass-through unchanged).
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloDomain Invalid domain
FloMatch Invalid src data: Unconstrained or TripleBand or bitonal
FloTechnique Invalid histogram shape or shape-params
The Point element can also be used to reshape an image's histogram using an appropriate LUT.
Math
XieFloMath
src: XieTypPhototag
domain: XieTypProcessDomain
operator: XieTypMathOp
band-mask: CARD8
Errors: FloAlloc, FloSource, FloDomain, FloMatch, FloOperator, FloValue
Events: none
Attribute Value
class Same as src
type Same as src
width Same as src
height Same as src
levels Same as src
Math applies a single operand mathematical operation to the source data on a point-wise basis.
Src is the Phototag of the element supplying source data. Domain may control the subset of the im-
age that will be operated upon. Operator is the mathematical operation to be applied. Band-mask
specifies which bands are to be operated upon.
Pixel computations that would lead to errors will yield valid server-dependent values (for example,
the log of a Constrained pixel value of zero might result in a value of zero). Using band-mask to se-
lect source data that have two (2) or less levels is not permitted.
All output data attributes are inherited from the source data.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloDomain Invalid domain
FloMatch Selected source data are bitonal (that is, 2 or less levels)
FloOperator Invalid operator
PasteUp
XieFloPasteUp
tiles: LISTofXieTypTile
width: CARD32
height: CARD32
constant: XieTypConstant
Errors: FloAlloc, FloSource, FloMatch
Events: none
Attribute Value
class Same as tiles
type Same as tiles
width width
height height
levels Same as tiles
PasteUp is an N-input translate operation that outputs data constructed from various source data tiles
or a constant value.
Each of the tiles specifies a src (the Phototag of the element supplying source data) and the coordi-
nates, dst-x and dst-y, where the tile belongs in the output data. Width and height specify the full ex-
tent of the output data. Constant is the fill value to as the output data for any region that is not speci-
fied as a tile.
Each region of the output data is defined by a tile's destination coordinates, dst-x and dst-y, and its src
dimensions. For output regions where no tile provides input, the value of constant is used. If tiles
overlap, a stacking order rule defines which pixel value will be output; the last tile (involved in the
overlap) in the list of tiles will provide the output pixel.
At least one tile must be supplied. Except for width and height, all attributes of each source tile must
match. In addition, for TripleBand input, inter-band dimensions within each tile must match.
No subsetting by band mask or ProcessDomain is provided.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid source tiles
No tiles were specified
FloMatch Incompatible attributes between tiles
Unequal inter-band dimensions within a tile (width or height)
Point
XieFloPoint
src: XieTypPhototag
lut: XieTypPhototag
domain: XieTypProcessDomain
band-mask: CARD8
Errors: FloAlloc, FloSource, FloDomain, FloMatch
Events: none
Attribute Value
class Same as lut
type Constrained
width Same as src
height Same as src
levels Same as lut
Point maps source pixel values to output pixel values using a lookup table (LUT) .
Src is the Phototag of the element supplying Constrained source data. Lut is the Phototag of the
element supplying the lookup table array(s). Domain may control the subset of source data that will
be operated upon. Band-mask specifies which bands are to be operated upon (all bands must be
specified if lut is SingleBand and src is TripleBand).
The output is Constrained with the width and height taken from src and class and levels taken from
lut. When src is SingleBand and lut is TripleBand, for the bands that are indicated by band-mask,
the output bands are remapped through their respective lut bands, whereas the other bands are just
replications of the single src band. If domain is used, the class and levels of lut must match those of
src.
Each lut array must contain sufficient entries so that all potential pixel values found in src can form a
valid index into the array. Generally each src pixel value is used directly as an index into a lut array.
When TripleBand src data are remapped through a SingleBand lut; however, pixel values from all
three src bands are combined to form an array index (for this case, width and height must match for
all bands). Figure 7-4 presents the algorithm for computing combined array indices.
LUT band-order
LUT indexing algorithm for combining pixel values from TripleBand data
LSFirst
index = value[0] + value[1] x levels[0] + value[2] x levels[0] x levels[1]
MSFirst
index = value[2] + value[1] x levels[2] + value[0] x levels[2] x levels[1]
Figure 7-4 Point's algorithm for computing combined LUT indices
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src or lut
FloDomain Invalid domain (for example, attempting to use domain with ServiceClass DIS)
FloMatch Unconstrained src data
domain is being used, but lut class or levels do not match those of src
lut does not contain enough entries (that is, length less than src levels)
lut is SingleBand and src is TripleBand, but band-mask is incomplete or inter-band
dimensions dont match
Unconstrain
XieFloUnconstrain
src: XieTypPhototag
Errors: FloAlloc, FloSource, FloMatch
Events: none
Attribute Value
class Same as src
type Unconstrained
width Same as src
height Same as src
levels Unknown
Unconstrain takes Constrained source data and produces Unconstrained data.
Src is the Phototag of the element supplying Constrained source data.
No subsetting by band mask or ProcessDomain is provided (the entire image is Unconstrained).
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloMatch Unconstrained src
GC-function is not a defined type in the core X protocol documentation. This table is taken from the list of alternative func-
tion values defined for the CreateCG protocol request.
Figure 6-1 illustrates the relationship between LUT class and image class and presents some usage examples.
Process Elements 7-3
8
Export Elements
Element categories
Export elements are used to send image data out of a Photoflo. Each export element has a single
Phototag source but does not provide an output connection. There are two types of export elements:
ExportResource elements export data to a server resource (DRAWABLE, LUT, Photomap, or ROI).
ExportClient elements produce data for client retrieval. They provide the input data for the GetCli-
entData protocol request.
Export to Client
ExportClient elements provide data for the client. Element parameters fully describe the format
or organization the data is to have as it is transported through the protocol stream. The data itself
must be retrieved using the GetClientData protocol request while the Photoflo is Active.
Servers are required to buffer a nonzero amount of data per ExportClient element. Beyond that
point execution may be suspended until the client retrieves sufficient data.
Events generated
ExportClient elements can generate ExportAvailable events to notify the client when the data is
available for retrieval. ExportAvailable events may be:
Disabled (that is, no event is sent)
Enabled only when data first becomes available from the element
Enabled each time the element's data buffer transitions from empty to nonempty
ExportClientHistogram
XieFloExportClientHistogram
notify: XieTypExportNotify
src: XieTypPhototag
domain: XieTypProcessDomain
Errors: FloAlloc, FloSource, FloDomain, FloMatch, FloValue
Events: none
ExportClientHistogram generates a histogram of the pixel values found in the source data. It pre-
pares histogram data that can be retrieved by the client using the GetClientData protocol request.
An event can be requested that will notify the client when histogram data becomes available.
Notify allows the client to be notified when the histogram data becomes available. Src is the Photo-
tag of the element supplying SingleBand Constrained source data. Domain may control the subset of
the source data from which the distribution will be generated.
The data generated for the client is a list of HistogramData where each entry consists of an value
(that is, a pixel value) followed by the count of pixels found with that value. If the number of pixels
for a given value exceeds the capacity of count (type CARD32), that count will be returned at the
maximum value (that is, 232-1). Pixel values that are not found in the data are not included in the
histogram data (that is, no entries are returned where count is zero).
If notify is true, the total number of histogram entries are reported in the data field of the Expor-
tAvailable event.
The histogram is returned as numeric values (see HistogramData), as such, the byte order of the data
is determined at core protocol connection setup time.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloDomain Invalid domain
FloMatch Unconstrained src data
TripleBand src data
FloValue Invalid notify
All data that are generated by ExportClientHistogram must be retrieved by the client using GetClientData before the Photoflo
can exit from the Active state.
Histograms of TripleBand images are not supported directly. However, BandSelect may be used to choose a single band of data, or
BandExtract may be used to combine data from multiple bands into a single band of data. A histogram of this single band of data
could then be generated using ExportClientHistogram.
ExportClientLUT
XieFloExportClientLUT
notify: XieTypExportNotify
src: XieTypPhototag
band-order: XieTypOrientation
start: XieTypTripletofCARD32
length: XieTypTripletofCARD32
Errors: FloAlloc, FloSource, FloValue
Events: none
ExportClientLUT allows data imported from an ImportLUT or ImportClientLUT element to be
retrieved by the client. The actual transport of lookup table data through the protocol stream is re-
quested using the GetClientData protocol request.
Notify allows the client to be notified when data become available. Src is the Phototag of the element
supplying lookup table data. Band-order is the order in which TripleBand arrays are transmitted
through the protocol stream. Start is the index of the first array entry that should be returned. Length
is the number of array entries that should be returned.
If notify is requested, the ExportAvailable event's data field will report the total number of array en-
tries that can be retrieved from the band specified by the event.
The size of each array entry is either 1, 2, or 4 bytes; the smallest size into which the output quanti-
zation levels can be stored. When array entries require multiple bytes, the byte order per entry is de-
termined in the same manner as other numeric data; it is the byte orientation established at core X
connection setup time.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloMatch start + length exceeds number of entries in an array
FloValue Invalid notify or band-order
When the client attempts to retrieve data from an ExportClientLUT element, the server responds with one or more complete array
entries per protocol reply (see GetClientData). All data must be retrieved by the client before the Photoflo can leave the Active
state.
ExportClientPhoto
XieFloExportClientPhoto
notify: XieTypExportNotify
src: XieTypPhototag
encode: XieTypEncodeTechnique
encode-params: <technique-dependent>
Errors: FloAlloc, FloSource, FloMatch, FloValue, FloTechnique
Events: none
ExportClientPhoto makes image data available to the protocol stream. The attributes of the exported
data are determined by the attributes of the source data. The format of the data is specified by the en-
code technique and encode-params. The actual transport of image data through the protocol stream
is requested using the GetClientData protocol request.
Notify allows the client to be notified when image data become available. Src is the Phototag of the
element supplying Constrained data. Encode is the EncodeTechnique that will be used to compress
of format the exported data. Encode-params is the list of additional parameters required by encode.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloMatch Unconstrained src data
FloValue Invalid notify
FloTechnique Invalid encode technique or encode-params
ServerChoice is not a valid encode technique for ExportClientPhoto.
Depending on encode, the export process may cause the data to be decoded, encoded, or, otherwise, reformatted by the server. If Ex-
portClientPhoto is fed directly from an ImportClientPhoto or ImportPhotomap element and the attributes of the raw data that
are given to the import element match the requirements of the encode technique, the raw data can bypass the normal decode function
of the import element and be forwarded directly to ExportClientPhoto (this is an implementation-specific optimization).
If TripleBand data are given to an encode technique that will interleave the output data BandByPixel, the dimensions of each src
band must match.
All data must be retrieved by the client, using the GetClientData protocol request, before the Photoflo can exit from the Active
state.
ExportClientROI
XieFloExportClientROI
notify: XieTypExportNotify
src: XieTypPhototag
Errors: FloAlloc, FloSource, FloValue
Events: none
ExportClientROI allows a list-of-rectangles, imported from an ImportROI or ImportClientROI
element, to be retrieved by the client. The actual transport of lookup table data through the protocol
stream is requested using the GetClientData protocol request.
Notify allows the client to be notified when data become available. Src is the Phototag of the element
supplying the list-of-rectangles. If notify is requested, the ExportAvailable event's data field will re-
port the total number of rectangles that can be retrieved.
Each rectangle is described using numeric values (see Rectangle), as such, the byte order of the data
is determined at core protocol connection setup time.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloValue Invalid notify
When the client attempts to retrieve data from an ExportClientROI element, the server responds with one or more complete Rec-
tangles per protocol reply (see GetClientData). All data must be retrieved by the client before the Photoflo can leave the Active
state.
Export to Resource
ExportResource elements emit data to server resources: either core X DRAWABLEs, or XIE LUT,
Photomap, or ROI resources.
For ExportResource elements that assign attributes to XIE resources, the association between the
resource identifier (XID) and the new attributes and data does not occur until the Photoflo success-
fully completes (that is, leaves the Active state). (See LUT, Photomap, and ROI resources in
Chapter 4.)
ExportDrawable
XieFloExportDrawable
src: XieTypPhototag
drawable: DRAWABLE
gc: GCONTEXT
dst-x: INT16
dst-y: INT16
Errors: FloAlloc, FloSource, FloDrawable, FloGC, FloMatch, FloValue
Events: none
ExportDrawable allows COLORMAP index data to be exported to a WINDOW or PIXMAP.
Src is the Phototag of the element supplying Constrained source data (index data assumed).
Drawable is the WINDOW or PIXMAP into which the data will be written. Gc is the GCONTEXT to be
used when transferring pixels to drawable. Dst-x and dst-y specify where the data should be placed in
drawable.
The following components are used from gc: function, plane-mask, subwindow-mode,
clip-x-origin, clip-y-origin, and clip-mask.
The levels of src must exactly match the depth of drawable and gc (that is, levels must be 2depth).
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloDrawable Invalid drawable
FloGC Invalid gc
FloMatch Invalid src data (TripleBand, levels does not match depth, or Unconstrained)
ExportDrawable assumes its input is COLORMAP index data. Sources of such data include: ImportClientPhoto, Import-
Drawable, ImportPhotomap, BandExtract, ConvertToIndex, Point, and elements that have processed index data.
ExportDrawablePlane
XieFloExportDrawablePlane
src: XieTypPhototag
drawable: DRAWABLE
gc: GCONTEXT
dst-x: INT16
dst-y: INT16
Errors: FloAlloc, FloSource, FloDrawable, FloGC, FloMatch, FloValue
Events: none
ExportDrawablePlane allows SingleBand single bit (bitonal) data to be exported to a WINDOW,
PIXMAP, or BITMAP.
Src is the Phototag of the element supplying Constrained bitonal source data. Drawable is the WIN-
DOW, PIXMAP, or BITMAP into which the data will be written. Gc is the GCONTEXT to be used
when transferring pixels to drawable. Dst-x and dst-y specify where the data should be placed in
drawable.
The following components are used from gc: function, plane-mask, foreground, back-
ground, fill-style, subwindow-mode, clip-x-origin, clip-y-origin, and clip-
mask. For the fill-style component of gc, values of FillSolid and FillTiled are treated
as synonyms for FillOpaqueStippled.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloDrawable Invalid drawable
FloGC Invalid gc
FloMatch Invalid src data (TripleBand, levels > 2, or not Constrained)
Bitonal data can be exported to a DRAWABLE of any depth if an appropriate GCONTEXT is supplied. The foreground and
background pixel values of gc can be used to map image pixels to COLORMAP colors during the export process.
ExportLUT
XieFloExportLUT
src: XieTypLUT
merge: BOOL
start: XieTypTripletofCARD32
Errors: FloAlloc, FloSource
Events: none
ExportLUT allows data imported from an ImportLUT or ImportClientLUT element to be saved in
an existing LUT resource.
Src is the Phototag of the element supplying lookup table data. Lut is the LUT to receive the data.
Merge specifies that new array entries from src should replace entries that already exist within lut.
Start is the index of the first array entry that should be written in lut.
If merge is false, start must be zero (0) for each band. In this case, lut will inherit the attributes of src
and be populated with its data. The previous attributes and data of lut are overwritten when the pho-
toflo completes.
If merge is true and lut has existing attributes, the data from src will replace the data from lut, begin-
ning at position start. The attributes of src must match those of lut, and the combination of start and
the length of src must specify a valid subrange existing within lut. If merge is true but lut has not yet
been populated, it is an error.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloLUT Invalid lut
FloMatch merge true and attributes do not match between src and lut
merge true and start + src length is not a subrange of lut
FloValue merge false and start is nonzero
ExportPhotomap
XieFloExportPhotomap
src: XieTypPhototag
photomap: XieTypPhotomap
encode: XieTypEncodeTechnique
encode-params: <technique-dependent>
Errors: FloAlloc, FloSource, FloPhotomap, FloTechnique
Events: none
ExportPhotomap allows data resulting from Photoflo operations to be saved in an existing Pho-
tomap.
Src is the Phototag of the element supplying source data. Photomap is the Photomap to receive the
data. Encode is the EncodeTechnique by which the image is to be compressed or formatted. Encode-
params is the list of additional parameters required by encode.
Photomap will inherit the attributes of src and be populated with its data. The previous attributes and
data of photomap are overwritten when the Photoflo completes.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloPhotomap Invalid photomap
FloTechnique Invalid encode technique or encode-params
Depending on encode, the export process may cause the data to be decoded, encoded, or, otherwise, reformatted by the server. If Ex-
portPhotomap is fed directly from an ImportClientPhoto or ImportPhotomap element and the attributes of the raw data that are
given to the import element match the requirements of the encode technique, the raw data can bypass the normal decode function of
the import element and be forwarded directly to ExportPhotomap (this is an implementation-specific optimization).
If encode is ServerChoice, the server is free to choose an encode technique for the exported data. An optional hint can be provided
to help the server make its choice, but the server can ignore the hint. PreferTime hints that retrieval performance is the desired metric,
whereas PreferSpace indicates that frugal use of storage space is more important. If ExportPhotomap is receiving data from an
adjacent upstream import element, ServerChoice may choose to pass the import elements input data directly to the Photomap; oth-
erwise, a lossless technique will be chosen. The actual technique chosen by the server can be obtained using QueryPhotomap after
the Photoflo completes.
If TripleBand data are given to an encode technique that will interleave the output data BandByPixel, the dimensions of each src
band must match.
ExportROI
XieFloExportROI
src: XieTypPhototag
roi: XieTypROI
Errors: FloAlloc, FloSource, FloROI
Events: none
ExportROI allows data imported from an ImportROI or ImportClientROI element to be saved in
an existing ROI.
Src is the Phototag of the element supplying a list-of-rectangles. Roi is the ROI to receive the data.
Roi will be populated with new data. The previous data of roi are overwritten after the Photoflo com-
pletes.
Error Cause
FloAlloc Insufficient resources
FloSource Invalid src
FloROI Invalid roi
Export Elements 8-1
9
Events and Errors
Events
ColorAlloc
XieEvnColorAlloc
instance: XieTypExecutable
src: XieTypPhototag
type: ConvertToIndex
color-list: XieTypColorList
color-alloc: XieTypColorAllocTechnique
data: CARD32
A ColorAlloc event notifies the client that a ConvertToIndex element has completed color allocation
but has produced a result of lesser fidelity than was requested using the technique that was specified
for the ConvertToIndex element.
Instance, src, and type identify the Photoflo and specific ConvertToIndex element from which the
ColorAlloc event originated. Color-list is the ColorList resource that received the allocated colors.
Color-alloc is the ColorAllocTechnique specified to the ConvertToIndex element. Data can be used
for other information that is specific to color-alloc.
DecodeNotify
XieEvnDecodeNotify
instance: XieTypExecutable
src: XieTypPhototag
type: { ImportClientPhoto, ImportPhotomap }
decode: XieTypDecodeTechnique
data-width: CARD32
data-height: CARD32
band-number: CARD8
aborted: BOOL
A DecodeNotify event notifies the client that anomalies were encountered while decoding a com-
pressed image (see the notify parameters of ImportClientPhoto and ImportPhotomap). Either an er-
ror has been encountered while decoding an image, or the image data received does not satisfy the
expected dimensions.
Instance, src, and type identify the Photoflo and element from which the DecodeNotify event origi-
nated. Decode is the DecodeTechnique being used. Data-width and data-height are the dimensions
discovered while decoding the data. Band-number associates the event with the band of the image
where the problem was encountered. Aborted is true if decoding was aborted or false if recovery was
possible.
Recovery from a decode error may result in some missing or garbled image data. This may also cause
the height of the decoded data to be less than was expected. If data-width or data-height do not
match the width and height specified to ImportClientPhoto, the image data is clipped or padded
(with zeros), as required, to enforce the ImportClientPhoto specified dimensions.
ExportAvailable
XieEvnExportAvailable
instance: XieTypExecutable
src: XieTypPhototag
type:{ ExportClientHistogram, ExportClientLUT, ExportClientPhoto ExportClientROI }
band-number: CARD8
data; LISTofCARD32
An ExportAvailable event notifies the client that an ExportClient element has data available
(see the notify parameter of the applicable ExportClient element). If notify was specified as
FirstData, this event will only be sent the first time data become available from the ExportClient
element. Otherwise (that is, NewData was specified) this event will be generated each time the
amount of data available changes from zero to nonzero.
Instance, src, and type identify the Photoflo and specific ExportClient element from which the
ExportAvailable event originated. Band-number associates the event with a specific band of the im-
age or LUT. Data is information specific to type (for example, the number of LUT entries or ROI
rectangles available).
Where there is a single ExportClient element, the client can just read bytes or be event-driven. For Photoflos containing multi-
ple ExportClient elements, the client should be event-driven.
ImportObscured
XieEvnImportObscured
instance: XieTypExecutable
src: XieTypPhototag
type: { ImportDrawable, ImportDrawablePlane }
window: WINDOW
x: INT16
y: INT16
width: CARD16
height: CARD16
An ImportObscured event notifies the client an ImportDrawable or ImportDrawablePlane ele-
ment has encountered obscured regions in a WINDOW that cannot be retrieved from BACKINGSTORE
(see the notify parameter of the import element). A separate ImportObscured event is returned for
each affected region.
Instance and src identify the Photoflo and the specific import element from which the ImportOb-
scured event originated. Window identifies the WINDOW. The obscured region of the window is
specified by x, y, width, and height.
Note: image data within obscured regions will be populated with the fill value supplied to the import element.
PhotofloDone
XieEvnPhotofloDone
instance: XieTypExecutable
outcome: XieTypPhotofloOutcome
A PhotofloDone event notifies the client that a Photoflo has left the Active state. It is enabled by the
notify parameter of the ExecutePhotoflo and ExecuteImmediate requests.
Instance identifies the Photoflo from which the PhotofloDone event originated. Outcome indicates
the reason the Photoflo left the Active state.
If the Photoflo terminated due to an error condition, the details concerning the error have preceded this event in an error message.
Resource Errors
The following error-codes are allocated from the extension error space to provide for the errors re-
turned by XIE:
Table 9-1 XIE Error codes
Error Cause
XieErrColorList The value for a color-list argument does not name a defined ColorList.
XieErrFlo . . . An error has been detected while defining, executing, or accessing a Photoflo.
See Table 9-2 for additional detail.
XieErrLUT The value for a lut argument does not name a defined LUT.
XieErrPhotoflo The value for a photoflo argument does not name a defined Photoflo.
XieErrPhotomap The value for a photomap argument does not name a defined Photomap.
XieErrPhotospace The value for a photospace argument does not name a defined Photospace.
XieErrROI The value for a roi argument does not name a defined ROI.
XIE also uses the core protocol errors: Access, Alloc, IDChoice, Length, Request, and Value.
Photoflo errors
If an error is detected while defining, executing, or accessing a Photoflo, a Flo-error is returned.
This single error-code is allocated from the extension error space for all Photoflo related errors. The
following subcodes are defined to provide the details of the error:
Table 9-2 Photoflo error subcodes
Error Cause
XieErrFloAccess Attempt to execute, modify, or redefine an Active Photoflo
Attempt to Get/Put client data from/to an Inactive Photoflo
XieErrFloAlloc Insufficient resources (for example, memory)
XieErrFloColormap An unknown COLORMAP has been specified
XieErrFloColorList An unknown ColorList has been specified
XieErrFloDomain Invalid domain Phototag:
source data is not a list-of-rectangles or control-plane
specified nonzero on a DIS server
XieErrFloDrawable An unknown DRAWABLE has been specified
XieErrFloElement An unknown PhotoElement type has been specified
Invalid PhotoElement type for request (for example, GetClientData from
Math)
Attempt to change or add a PhotoElement type using ModifyPhotoflo
XieErrFloGC An unknown GCONTEXT has been specified
XieErrFloID Invalid Executable:
an unknown Photoflo has been specified
an unknown Photospace has been specified
XieErrFloLength A PhotoElement was received with the incorrect number of bytes
XieErrFloLUT An unknown LUT has been specified
XieErrFloMatch Some parameter or pair of parameters has the correct type and range, but it
fails to match in some other way required by the PhotoElement
XieErrFloOperator An unknown operator has been specified (for example, ArithmeticOp,
MathOp, and so on)
XieErrFloPhotomap An unknown Photomap has been specified
XieErrFloROI An unknown ROI has been specified
XieErrFloSource An invalid Phototag has been specified:
zero, but a Phototag is required
downstream from the particular PhotoElement
beyond the bounds of the Photoflo
XieErrFloTechnique An unknown technique has been specified
The wrong number of technique specific parameters have been supplied
Invalid technique specific parameters have been specified
XieErrFloValue Some numeric value falls outside of the range of values accepted by the Pho-
toElement
XieErrFloImplementation
almost blank
Events and Errors 9-1
A
Techniques
Standard and Private Techniques
For some XIE operations, several recognized algorithms or techniques offer varying tradeoffs between
quality of results and performance. Also, in some cases, different techniques are required due to an
image's class or content. In general, techniques that are specified for import and export elements
identify image compression schemes, and techniques that are specified for process elements identify
various image processing or enhancement algorithms.
Several standard techniques are defined in this appendix. Standard techniques are those that are well
known to the image processing community. They are further categorized in this document as re-
quired, optional, or excluded (see Table B-2). While required techniques must be implemented in all
servers, it is expected that most optional techniques will also be widely available. Some techniques
are excluded from certain subsets.
Vendors may choose to extend XIE with their own private techniques to provide for their particular
needs. Therefore, private techniques are likely to be available only on a particular vendor's platforms.
Technique numbers
Standard and private techniques can be differentiated by their technique numbers. The most signifi-
cant bit of the technique number is zero (0) for standard techniques and one (1) for private tech-
niques. Standard technique numbers are defined in this document (see Appendix C). Private tech-
nique numbers are assigned dynamically (the method for generating private technique numbers is
chosen by the server implementor). Because private technique numbers are not statically defined, the
number to name-string mapping must be obtained on a per-server basis via the QueryTechniques
protocol request.
Technique names
The name string for standard techniques contains only the name of the algorithm or compression
scheme (for example, ERROR-DIFFUSION or CCITT-G32D). Private technique name strings
also include the name of the vendor that owns the rights to the technique (for example,
_PHOTOCO_SQUASH-BITS). Because the organization name is encompassed by _
(underscore) characters, the leading underscore provides another means by which standard techniques
can be can differentiated from private techniques.
Default Techniques
In some cases, it is appropriate to assign a default technique. A default technique is a synonym that
must be bound to a standard or private technique. Where there is no required standard technique, a
default technique must be defined that is bound to an optional or a private technique. No default is
defined in cases where it would be inappropriate (for example, decode techniques describing client
data).
Technique parameters
For each occurrence of a technique within an element definition, allowance is made to pass parame-
ters that are specific to the technique. Some techniques have defined parameters, and others have
none. For techniques that do have defined parameters, the QueryTechniques request can be invoked
to determine if the parameters must be supplied. If the parameters are optional and they are omitted
by the client, the server will supply implementation specific default values in their place.
If the default technique is requested, no additional parameters are accepted (implementation specific
default values will be provided for parameters defined for the technique to which Default is bound).
Technique information
The QueryTechniques request returns information about All techniques, all Default techniques, or a
group of techniques that are functionally similar (for example, Dither, Encode, Geometry, and so
on). The following information is returned about the selected techniques:
needs-parameters Indicates that the technique requires additional parameters; if false, the technique takes no
parameters, or its parameters are optional. If the parameters are optional, they can be totally
omitted, otherwise they must all be supplied.
group Identifies which group the technique belongs to.
number Specifies the numeric identifier assigned to the technique (MS bit is zero for standard tech-
niques, or one for private techniques).
speed Specifies the server's assessment of the speed of this technique relative to other techniques in
the same group (where 0 is the slowest, and 255 is the fastest).
name Identifies the technique name string in the form:
<STANDARD-TECHNIQUE-NAME> or
_<ORGANIZATION-NAME>_<PRIVATE-TECHNIQUE-NAME>
The remainder of this appendix provides a complete description of each technique and its parameters.
Color Allocation Techniques
Color allocation techniques allocate or match colors or gray shades from a COLORMAP. Cells allo-
cated from a dynamic COLORMAP are recorded in a ColorList. If the COLORMAP is static, im-
age pixels can only be matched to existing COLORMAP entries; no allocations are made and no Col-
orList needs to be specified.
AllocAll
Parameters
fill: CARD32
AllocAll allocates a read-only COLORMAP cell for each new pixel found. If the COLORMAP runs out
of cells, the remaining new pixels are mapped to fill. A ColorAlloc event can be sent if it is neces-
sary to use fill. AllocAll is only appropriate for dynamic COLORMAPs and requires that the number
of discrete image pixels fit within the size of the COLORMAP to avoid running out of cells.
Match
Parameters
match-limit: XieTypFloat
gray-limit: XieTypFloat
Match allows a trade-off between image fidelity and COLORMAP usage via a pair of granularity pa-
rameters [ ]. The highest priority is given to allocating read-only cells in a sequence that provides an
even distribution of pixels throughout the colorspace. Secondary priority is given to the frequency of
usage of image pixels. Any image pixel that is a close enough match to an existing read-only cell will
share that cell (where close is determined by the granularity controls). For other image pixels, new
read-only allocations are made. When no more cells are available, each remaining image pixel is
matched to the closest read-only cell. Match is appropriate for both static and dynamic COL-
ORMAPs. For the sake of computational efficiency, the number of discrete image pixels should not
exceed the size of the COLORMAP.
Match-limit and gray-match control the allocation of colors and gray shades, respectively. The mini-
mum value (0.0) specifies exact matches (within the limits of the COLORMAP). The maximum value
(1.0) encompasses the entire colorspace within which no new cells are allocated. A ColorAlloc event
can be sent if the COLORMAP runs out of cells.
Requantize
Parameters
max-cells: CARD32
Requantize first reduces the total number of discrete pixels values in the image to be no more than a
specified number and, then, allocates the resulting pixels values as read-only cells from the COLOR-
MAP. One method of accomplishing this reduction process can be found in [ ].
Max-cells specifies the maximum number of COLORMAP allocations to allow. If max-cells is zero or
greater than the number of unallocated COLORMAP cells, the reduction algorithm will restrict its out-
put to the number of free cells. A ColorAlloc event can be sent if the number of pixels had to be re-
stricted to a lesser number than max-cells due to a lack of free COLORMAP cells. Requantize is only
appropriate for dynamic COLORMAPs.
Constrain Techniques
ClipScale
Parameters
input-low: XieTypConstant
input-high: XieTypConstant
output-low: XieTypLevels
output-high: XieTypLevels
For each band, output pixels will be clipped to the range [output-low, output-high].
If input-low is less than input-high, then all pixels less than or equal to input-low will map to output-
low, and all pixels that are greater than or equal to input-high will map to output-high. All interme-
diate pixel values are scaled proportionately to the output range. Nonintegral output values are
rounded to the nearest integer.
If input-low is greater than input-high then all pixels that are greater than or equal to input-low will
map to output-low, and all pixels that are less than or equal to input-high will map to output-high.
All intermediate pixel values will be linearly mapped to the output range such that input-low maps to
output-low, and input-high maps to output-high. Nonintegral output values are rounded to the near-
est integer.
If input-low equals input-high, or if output-low or output-high exceeds levels-1, a FloTechnique error
is generated.
HardClip
Parameters
< none >
HardClip constrains the data such that all negative pixels are set to zero, and all pixels greater than
levels-1 are set to levels-1. All other pixels are rounded to the nearest integer value.
Convert From RGB
CIELab
Parameters
matrix: XieTypMatrix
white-adjust: XieTypWhiteAdjustTechnique
white-params: <technique-dependent>
Matrix is a 3x3 RGB to CIEXYZ conversion matrix (the source white point is also encoded in ma-
trix). White-adjust is the WhiteAdjustTechnique that can be used to shift the white point of the out-
put data. White-params is the list of parameters required by white-adjust.
The input DataType can be Constrained or Unconstrained; the output DataType is always Uncon-
strained. When the input is Constrained, the data are normalized to the range [0, 1] (that is, scaled
by 1/(levels - 1) prior to the conversion.
CIEXYZ
Parameters
matrix: XieTypMatrix
white-adjust: XieTypWhiteAdjustTechnique
white-params:<technique-dependent>
Matrix is a 3x3 RGB to CIEXYZ conversion matrix (the source white point is also encoded in ma-
trix). White-adjust is the WhiteAdjustTechnique that can be used to shift the white point of the out-
put data. White-params is the list of parameters required by white-adjust.
The input DataType can be Constrained or Unconstrained; the output DataType is always Uncon-
strained. When the input is Constrained, the data are normalized to the range [0, 1] (that is, scaled
by 1/(levels - 1) prior to the conversion.
YCbCr
Parameters
luma: XieTypConstant
levels: XieTypLevels
bias: XieTypConstant
Luma represents the proportions of red, green, and blue in the luminance band, Y. Levels determines
the output levels if src is Constrained (otherwise, levels is ignored). Bias is used to add an offset to
the output pixels values.
Source data may be Constrained or Unconstrained; the output type will match.
YCC
Parameters
luma: XieTypConstant
levels: XieTypLevels
scale: XieTypFloat
Luma represents the proportions of red, green, and blue in the luminance band, Y. Levels determines
the output levels if src is Constrained (otherwise, levels is ignored). Scale is used to compress the
output pixels (a typical value is about 1.35 to 1.4 in the literature).
Convert To RGB
CIELab
Parameters
matrix: XieTypMatrix
white-adjust: XieTypWhiteAdjustTechnique
white-params: <technique-dependent>
gamut-compress: XieTypGamutTechnique
gamut-params: <technique-dependent>
Matrix is a 3x3 CIEXYZ to RGB conversion matrix (the target white point is also encoded in matrix).
White-adjust is the WhiteAdjustTechnique that can be used to shift the white point of the source data
prior to conversion. White-params is the list of parameters required by white-adjust. Gamut-
compress is the GamutTechnique that can be used to keep the output pixels within the bounds of the
RGB colorspace. Gamut-params is the list of parameters required by gamut-compress.
The input DataType must be Unconstrained; the output DataType is also Unconstrained.
CIEXYZ
Parameters
matrix: XieTypMatrix
white-adjust: XieTypWhiteAdjustTechnique
white-params: <technique-dependent>
gamut-compress: XieTypGamutTechnique
gamut-params: <technique-dependent>
Matrix is a 3x3 CIEXYZ to RGB conversion matrix (the target white point is also encoded in matrix).
White-adjust is the WhiteAdjustTechnique that can be used to shift the white point of the source data
prior to conversion. White-params is the list of parameters required by white-adjust. Gamut-
compress is the GamutTechnique that can be used to keep the output pixels within the bounds of the
RGB colorspace. Gamut-params is the list of parameters required by gamut-compress.
The input DataType must be Unconstrained; the output DataType is also Unconstrained.
YCbCr
Parameters
luma: XieTypConstant
levels: XieTypLevels
bias: XieTypConstant
gamut-compress: XieTypGamutTechnique
gamut-params: <technique-dependent>
Luma represents the proportions of red, green, and blue in the luminance band, Y. Levels determines
the output levels if src is Constrained (otherwise, levels is ignored). Bias is used to remove any offset
from the source pixels values. Gamut-compress is the GamutTechnique that can be used to keep the
output pixels within the bounds of the RGB colorspace. Gamut-params is the list of parameters re-
quired by gamut-compress.
Source data may be Constrained or Unconstrained; the output type will match.
YCC
Parameters
luma: XieTypConstant
levels: XieTypLevels
scale: XieTypFloat
gamut-compress: XieTypGamutTechnique
gamut-params: <technique-dependent>
Luma represents the proportions of red, green, and blue in luminance Y. Levels determines the output
if src is Constrained (otherwise, levels is ignored). Scale is used to expand the source pixels (a typical
value is about 1.35 to 1.4 in the literature). Gamut-compress is the GamutTechnique that can be
used to keep the output pixels within the bounds of the RGB colorspace. Gamut-params is the list of
parameters required by gamut-compress.
Source data may be Constrained or Unconstrained; the output type will match.
Convolution Edge Techniques
Various methods of handling edge conditions are provided for Convolve. These techniques determine
what pixel values are used when Convolve requires data beyond the image bounds. ConvolveTech-
niques only come into play when the kernel is positioned partially off the edge of the image. Data
around the edges of a ProcessDomain are convolved with adjacent image pixels wherever possible.
Constant
Parameters
constant: XieTypConstant
Constant uses the value specified by constant if pixels are required from beyond the edge of the im-
age.
Replicate
Parameters
< none >
Replicate uses the nearest edge pixel value if pixels are required from beyond the edge of the image.
Decode Techniques
UncompressedSingle
Parameters
fill-order: XieTypOrientation
pixel-order: XieTypOrientation
pixel-stride: CARD8
left-pad: CARD8
scanline-pad: CARD8
UncompressedTriple
Parameters
fill-order: XieTypOrientation
pixel-order: XieTypOrientation
band-order: XieTypOrientation
interleave: XieTypInterleave
pixel-stride: XieTypTripletofCARD8
left-pad: XieTypTripletofCARD8
scanline-pad: XieTypTripletofCARD8
These techniques are used when no compression scheme has been applied to the image data. They are
used for SingleBand and TripleBand data, respectively. Their parameters define the format of the
DataStream of uncompressed data (the server may reformat the data as it chooses prior to processing
or storage).
The following parameters are common to both techniques:
* When multiple pixels are put in the same byte or a pixel spans multiple bytes, fill-order specifies
whether the pixels (or parts of pixels) are packed into the most or least significant bits of a byte
first.
* For pixels that span a byte boundary, pixel-order defines whether the most or least significant bits
of the pixel are transported first within the DataStream.
* Pixel-stride is the number of bits between the start of consecutive pixels within a scanline. It
must be at least enough bits to contain the number of input levels.
* Left-pad is the number of pad bits preceding the first image pixel in each scanline. If the server's
Alignment attribute is Alignable or pixel-stride fits the definition of Alignable, the value of left-
pad must be a multiple of pixel-stride or a multiple of 8; otherwise, left-pad may be any arbitrary
value.
* Scanline-pad defines a multiple of bytes to which each scanline is padded; valid values are: 0
(not aligned), 1, 2, 4, 8, and 16. The total number of bits-per-scanline in the DataStream in-
cludes: left-pad, the image data (width x pixel-stride), and sufficient additional bits to satisfy
scanline-pad.
The following parameters are only used by UncompressedTriple:
* Band-order is the order of the image bands or image planes as they are transmitted through the
protocol stream.
* Interleave describes how the image bands are interleaved (per pixel within a single plane, or sent
as three separate planes). If interleave is BandByPixel, inter-band dimensions must match (that
is, the widths and the heights of all bands must match).
CCITT-G31D
Parameters
encoded-order: XieTypOrientation
radiometric: BOOL
normal: BOOL
CCITT-G31D is the CCITT group 3 one dimensional encoding technique as defined by [ ].
Encoded-order specifies the bit-order of the encoded data. Radiometric specifies that white runs in
the encoded data should be represented as image ones upon decode (maximum intensity), or, con-
versely, they will be decoded as image zeros if radiometric is false. Normal specifies that the data
was processed according to its normal fill-order when it was originally encoded .
CCITT-G32D
Parameters
encoded-order: XieTypOrientation
radiometric: BOOL
normal: BOOL
CCITT-G32D is the CCITT group 3 two dimensional encoding technique as defined by [1].
Encoded-order specifies the bit-order of the encoded data. Radiometric specifies that white runs in
the encoded data should be represented as image ones upon decode (maximum intensity), or, con-
versely, they will be decoded as image zeros if radiometric is false. Normal specifies that the data
was processed according to its normal fill-order when it was originally encoded 2.
CCITT-G42D
Parameters
encoded-order: XieTypOrientation
radiometric: BOOL
normal: BOOL
CCITT-G42D is the CCITT group 4 two dimensional encoding technique as defined by [ ].
Encoded-order specifies the bit-order of the encoded data. Radiometric specifies that white runs in
the encoded data should be represented as image ones upon decode (maximum intensity), or, con-
versely, they will be decoded as image zeros if radiometric is false. Normal specifies that the data
was processed according to its normal fill-order when it was originally encoded 2.
JPEG-Baseline
Parameters
interleave: XieTypInterleave
band-order: XieTypOrientation
up-sample: BOOL
JPEG-Baseline is the baseline Huffman DCT encoding technique that is defined in [ ]. Only JPEG
Interchange Format (JIF) is supported (that is, all tables, compressed data, and so on are embedded in
the data stream, all delineated by markers).
Interleave determines if all bands of a TripleBand image will be interleaved within a single encoded
stream or if three separate encoded streams are expected. Band-order specifies the order in which the
image bands were originally encoded. Up-sample specifies that, if any bands in an interleaved en-
coded data stream are down-sampled, they should be up-sampled by the JPEG decoder.
Interleave, band-order, and up-sample are ignored for SingleBand images, and up-sample is always
ignored if interleave is BandByPlane. If up-sample is false and some of the encoded bands of an in-
terleaved image were down-sampled, an alternative method for up-sampling the image would be to
use a Geometry element with appropriate band-mask and sample technique parameters.
JPEG-Lossless
Parameters
interleave: XieTypInterleave
band-order: XieTypOrientation
JPEG-Lossless is the Huffman predictive sequential lossless encoding technique that is defined in [1].
Interleave describes how the bands of TripleBand data are interleaved; either all bands are inter-
leaved within a single encoded stream, or three separate encoded streams are expected. Band-order
specifies the order in which the image bands were originally encoded.
Interleave and band-order are ignored for SingleBand images.
TIFF-2
Parameters
encoded-order: XieTypOrientation
radiometric: BOOL
normal: BOOL
TIFF-2 is modified Huffman encoding as described in [ ]. (TIFF compression scheme 2).
Encoded-order specifies the bit-order of the encoded data. Radiometric specifies that white runs in
the encoded data should be represented as image ones upon decode (maximum intensity), or, con-
versely, they will be decoded as image zeros if radiometric is false. Normal specifies that the data
was processed according to its normal fill-order when it was originally encoded .
TIFF-PackBits
Parameters
encoded-order: XieTypOrientation
normal: BOOL
TIFF-PackBits is byte-oriented run-length encoding as described in [1] (TIFF compression scheme
32773).
Encoded-order specifies the bit-order of the encoded data. Normal specifies that the data was proc-
essed according to its normal fill-order when it was originally encoded 2.
Dithering Techniques
Dithering reduces the z-resolution or number of quantization levels in a continuous tone image. It
simulates the visual appearance of the original image by substituting the original continuous tone data
with patterns of lower z-resolution data. In ordered dither, fixed patterns are used. In error-diffusion
dither, the patterns are somewhat random and generally less distracting to the eye. A thorough treat-
ment of dithering techniques can be found in [ ].
ErrorDiffusion
Parameters
< none >
ErrorDiffusion dither is an image level reduction process where the difference (error) between output
pixel values and input pixel values is fed back through a filter to be applied to future input pixels.
Thus, past quantization errors are negatively distributed or diffused into the yet to be requantized im-
age.
Figure A-1 Diagram of the ErrorDiffusion algorithm
An analysis of various error filters is presented in chapter 8 of [1]. One popular error filter is de-
scribed in [ ].
Ordered
Parameters
threshold-order: CARD8
Dispersed-dot Ordered dither replaces a matrix, or block, of pixels with a patterned matrix of pixels.
This patterned matrix of pixels is applied across the entire image. Because these patterns may intro-
duce artifacts that are distracting to the eye, the threshold-order parameter is available to determine
the size of the dither matrix, and, therefore, the number of levels that can be simulated. If the value of
threshold-order is M, the threshold matrix can simulate 2M+1 levels.
For more information refer to [ ], and chapter 6 of [ ].
Encode Techniques
ServerChoice (only valid for ExportPhotomap)
Parameters
preference: CARD8 { PreferDefault, PreferSpace, PreferTime }
ServerChoice allows the server to choose an encode technique. An optional hint can be provided to
help the server make its choice, but the server is not obligated to obey the hint. PreferTime hints that
retrieval performance is the desired metric; PreferSpace indicates that frugal use of storage space is
more important. Normally, ServerChoice must choose a lossless encode technique, but when data is
received from an adjacent upstream import element, it may choose to pass the import elements input
data directly to the Photomap.
UncompressedSingle
Parameters
fill-order: XieTypOrientation
pixel-order: XieTypOrientation
pixel-stride: CARD8
scanline-pad: CARD8
UncompressedTriple
Parameters
fill-order: XieTypOrientation
pixel-order: XieTypOrientation
band-order: XieTypOrientation
interleave: XieTypInterleave
pixel-stride: XieTypTripletofCARD8
scanline-pad: XieTypTripletofCARD8
UncompressedSingle and UncompressedTriple specify that no compression scheme is to be applied
to the image data. They are used for SingleBand and TripleBand data, respectively. Their parameters
define the format of the DataStream of uncompressed data that is made available for client retrieval
via GetClientData.
The following parameters are common to both techniques:
* When multiple pixels are put in the same byte or a pixel spans multiple bytes, fill-order specifies whether
the pixels (or parts of pixels) are packed into the most or least significant bits of a byte first.
* For pixels that span a byte boundary, pixel-order defines whether the most or least significant bits of the
pixel are put first within the DataStream.
* Pixel-stride is the number of bits between the start of consecutive pixels within a scanline. It must be at
least enough bits to contain the number of src levels.
* Scanline-pad defines a multiple of bytes to which each scanline is padded; valid values are: 0 (not aligned),
1, 2, 4, 8, and 16.
The following parameters are only used by UncompressedTriple:
* Band-order is the order of the image bands or image planes as they are transmitted through the protocol
stream.
* Interleave describes how the bands are interleaved (per pixel within a single plane, or sent as three separate
planes). Export of down-sampled BandByPixel data is not supported (that is, all bands must have equal
widths and equal heights).
CCITT-G31D
Parameters
align-eol: BOOL
radiometric: BOOL
encoded-order: XieTypOrientation
CCITT-G31D is the CCITT group 3 one dimensional encoding technique as defined by [ ].
Align-eol, if true, specifies that sufficient fill bits must precede EOL codes to guarantee that each
EOL will end on a byte boundary (thus EOL will be a nibble of 0 followed by a byte of 1: xxxx,00002
0000,00012). Radiometric specifies that image ones will be encoded as white runs, or, conversely,
image zeros will be encoded as white runs if radiometric is false. Encoded-order specifies the bit-
order for the encoded data.
CCITT-G32D
Parameters
uncompressed: BOOL
align-eol: BOOL
radiometric: BOOL
encoded-order: XieTypOrientation
k-factor: CARD32
CCITT-G32D is the CCITT group 3 two dimensional encoding technique as defined by [1].
Uncompressed, if true, will enable the use of the uncompressed-mode CCITT extension. If true,
align-eol specifies that sufficient fill bits must precede EOL codes to guarantee that each EOL will
end on a byte boundary (thus EOL will be a nibble of 0 followed by a byte of 1: xxxx,00002
0000,00012). Radiometric specifies that image ones will be encoded as white runs, or, conversely,
image zeros will be encoded as white runs if radiometric is false. Encoded-order specifies the bit-
order for the encoded data. K-factor specifies the number of 2D scanlines to produce for each 1D
scanline.
CCITT-G42D
Parameters
uncompressed: BOOL
radiometric: BOOL
encoded-order: XieTypOrientation
CCITT-G42D is the CCITT group 4 two dimensional encoding technique as defined by [ ].
If true, uncompressed will enable the use of the uncompressed-mode CCITT extension. Radio-
metric specifies that image ones will be encoded as white runs, or, conversely, image zeros will be
encoded as white runs if radiometric is false. Encoded-order specifies the bit-order for the encoded
data.
JPEG-Baseline
Parameters
interleave: XieTypInterleave
band-order: XieTypOrientation
horizontal-samples: XieTypTripletofCARD8
vertical-samples: XieTypTripletofCARD8
q-table: LISTofCARD8
ac-table: LISTofCARD8
dc-table: LISTofCARD8
JPEG-Baseline is baseline Huffman DCT encoding as defined by [ ]. A stream of JPEG Interchange
Format (JIF) data is produced (that is, all tables, compressed data, and so on, delineated by markers).
Interleave determines if all bands of a TripleBand image will be interleaved within a single encoded
stream or if three separate encoded streams will be produced. Band-order specifies the order in which
the bands are encoded. Horizontal-samples and vertical-samples are the horizontal and vertical sam-
pling factors. Q-table is the quantization table. Ac-table specifies the AC Huffman table and dc-
table specifies the DC Huffman table.
One q-table per band or a single q-table may be shared between all bands. Generally, there is a single
AC/DC pair of Huffman tables, but, for TripleBand BandByPixel data, there may be two pairs of ta-
bles (one for the luminance band and the other for the chromanance bands). If any table is specified
with zero length, it indicates that the server implementor is to supply that table (for example, the ex-
ample tables defined in [1]).
Interleave, band-order, horizontal-samples, and vertical-samples are ignored for SingleBand images,
and horizontal-samples and vertical-samples are always ignored if interleave is BandByPlane. Horizon-
tal-samples and vertical-samples share the definitions and restrictions stipulated for parameters Hi and Vi,
respectively, that are specified in annexes A and B of [1].
JPEG-Lossless
Parameters
interleave: XieTypInterleave
band-order: XieTypOrientation
predictor: { PredictorNone None
PredictorA A
PredictorB B
PredictorC C
PredictorABC A+B-C
PredictorABC2 A+((B-C)/2)
PredictorBAC2 B+((A-C)/2)
PredictorAB2 } (A+B)/2
table: LISTofCARD8
JPEG-Lossless, corresponds to frames encoded using Huffman, predictive sequential lossless encod-
ing as defined by [1]. A DataStream of JPEG Interchange Format (JIF) data is returned (that is, all
tables, compressed data, and so on, delineated by markers).
Interleave determines if all bands of a TripleBand image will be interleaved within a single encoded
stream or if three separate encoded streams will be produced. Band-order specifies the order in which
the bands are encoded. Interleave and band-order are ignored for SingleBand images.
Predictor is the predictor selection value (one per band). Table is the lossless entropy encoding table
(up to one per band). Specifying a table of length zero indicates that the server implementor should
supply a table (for example, the example tables defined in [1]).
TIFF-2
Parameters
radiometric: BOOL
encoded-order: XieTypOrientation
TIFF-2 is modified Huffman compression as described in [ ] (TIFF compression scheme 2).
Radiometric specifies that image ones will be encoded as white runs, or, conversely, image zeros
will be encoded as white runs if radiometric is false. Encoded-order specifies the bit-order for the
encoded data.
TIFF-PackBits
Parameters
encoded-order: XieTypOrientation
TIFF-PackBits is byte-oriented run-length encoding as described in [1] (TIFF compression scheme
32773).
Encoded-order specifies the bit-order of the encoded data.
Gamut Compression Techniques
GamutTechnique defines the gamut compression techniques used by the ConvertToRGB element.
It deals with converted colors that fall outside the gamut of the RGB colorspace.
None
Parameters
< none >
None specifies that no gamut compression is required.
ClipRGB
Parameters
< none >
ClipRGB ensures that Unconstrained output pixel values remain within the implicit range [0.0, 1.0].
Note that Constrained data are clipped to the range [0, levels-1] by definition.
Geometry Techniques
Antialias
Parameters
< none >
Some Geometry techniques produce artifacts when replicating pixels or sampling the input image at
distinct intervals. One example are the jaggies that one often sees along diagonal lines and curved
objects in an image. Another indication is that some techniques, such as, nearest neighbor, seem to
drop image detail. For example, one could scale down an image by four simply by selecting every
fourth row and column in the input image. Given an image with a set of randomly placed vertical
lines, each line will have a 75% chance of being dropped in the output image. As a result, the output
image in the worst case may have little resemblance to the input image.
Antialiasing techniques incorporate information from an area of pixels in the input image in order
to produce each output pixel. This implies that line dropouts and other artifacts will occur less often,
and the output image may have markedly better resemblance to the input image.
The techniques AntialiasByArea and AntialiasByLowpass are two examples of specific antialiasing
algorithms. Antialias may be mapped to either of them or to a vendor-private algorithm. All pa-
rameters for the specific algorithm employed are defaulted by the server.
AntialiasByArea
Parameters
simple: INT16
Geometry may be used to scale an image down from a larger size to a smaller size. This will decrease
the density of pixels per unit area in the image. In Figure A-2(a), an input image at the original
resolution is displayed. It is to be reduced to the grid shown in Figure A-2(b), where the original im-
age is superimposed on the new, lower density grid. Figure A-2(c) shows a possible result of using
nearest-neighbor sampling to fill the output grid. Specifically, the output pixel's upper-left corner is
matched against the nearest upper-left corner of pixels in the input image. If the nearest input pixel
is black, the output pixel is filled with black. Otherwise, it is filled with white. While the pixel in-
tensities (in this case, pure black and pure white) are preserved by this operation, the overall image
shape is changed.
Figure A-2 Effect of sampling technique when scaling to a lower pixel density
In Figure A-2(d), the output image is computed by assigning to each output pixel the weighted aver-
age of the intensity values of input pixels that fall within its area. That is, the four corners of the out-
put pixel are projected back onto the input image. The input pixels that lie within this area contribute
according to the following:
is the intensity of output pixel . stands for the projection of into the input image
space. is the area of in the input image space. is the area of the intersection
of with the rectangular locus of . The sum progresses over all pixels in the input image (note
that for most such pixels, the area of intersection will be zero).
Figure A-3 illustrates the calculation for a single output pixel, P, whose projection intersects nine
input pixels to various degrees. Note that the number of pixels intersected depends on the degree of
scaling involved. A greater reduction in producing the output image will cause more input pixels to
be intersected per output pixel. Also, in case of nonorthogonal rotation of the image, the areas of
intersection will not be rectangular in general.
Figure A-3 Illustration of an output pixel mapping back to the input image
Because of the computational complexity of this method, two approximations are supported. If sim-
ple is nonzero, the pixels covered by the projected area will be averaged without regard to the relative
amount of gray area that they contain: if they are touched by the area, they are included in a simple
average. If simple is set to N, with N odd and greater than one (3,5,7, ...), then only the center point
of the output pixel is projected, and a simple average is taken of an N by N window centered on the
projection. For best results, N should correspond roughly to the amount of scaling that will be done.
AntialiasByLowpass
Parameters
kernel-size: INT16
Geometry may be used to scale an image down from a larger size to a smaller size. This will decrease
the density of pixels per unit area in the image. Figure A-2 demonstrates the difference between
scaling an image down using nearest-neighbor vs. antialias techniques. AntialiasByArea preserves
shape, as in Figure A-2 (d) but can be very slow computationally. The method presented here repre-
sents an approximation to AntialiasByArea , which can be faster, yet provides similar results.
Figure A-4 demonstrates how antialiasing can be produced using a low-pass filter. A 3x3 boxcar ker-
nel is passed over the original input image, in Figure A-4 (b). This image is shown superimposed on
the lower density grid in Figure A-4 (c). Nearest neighbor sampling by selecting the value of the in-
put pixel in the upper-left corner of the output pixel area results in the image in Figure
A-4(d). As was the case with AntialiasByArea, the overall structure of the input image is main-
tained.
Figure A-4 Sequence producing an antialiased image using a low-pass filter
The user is allowed to select the size of the image kernel via the kernel-size parameter. For best re-
sults, kernel-size should be chosen to correspond roughly to the amount of scaling that will be done.
Note that the server chooses the best kernel for the appropriate size; the values used in the kernel are
not alterable by the client application. Clients wishing to specify the kernel in more detail should use
Convolve directly.
BilinearInterpolation
Parameters
< none >
Geometry maps each pixel (x',y') in the output image to the coordinate location (x,y) in the input
image by:
(1)
It is not unusual that the input location (x,y), so derived will be nonintegral and will not correspond
exactly to a single pixel in the input image. In this case, we can obtain an interpolated value by first
interpolating its neighbors in the X direction followed by an interpolation in the Y direction, as de-
picted below.
Pixel grid locations P, Q, R, and S are integral. Pixel location X = (x,y)T, obtained from the map-
ping equation above, differs from P by fractional amounts s in the x direction and t in the y direc-
tion. Point pq is the projection of X on line PQ, and point sr is the projection of X on line SR.
Let I(P) be the value of the input image at coordinate P, if P is within the image extent. Otherwise,
let I(P) be constant, where constant is the pixel value passed to the Geometry element. A value of
I(X)must be estimated from I(P), I(Q), I(R), and I(S). We may obtain estimates of I(pq)
and I(sr) by:
I(pq) = (1 - s) * I(P) + s * I(Q)
I(sr) = (1 - s) * I(S) + s * I(R)
Given values for I(pq) and I(sr), I(X) is obtained by interpolating in the y direction:
I(X) = (1 - t) * I(pq) + t * I(sr)
Thus
I(X) = (1 - s) * (1 - t) * I(P) + (1 - s) * t * I(S) + s * (1 - t) * I(Q) + s * t * I(R)
Note that I(X) provides sensible values for the extreme values of s and t (0 and 1) and for
s = t = 1/2.
Gaussian
Parameters
sigma: XieTypFloat
normalize: XieTypFloat
radius: CARD8
simple: BOOL
Sigma is the drop-off rate; normalize is a normalization constant; radius defines the extent of com-
putation; and, simple allows the use of an approximate form.
Geometry maps each pixel (x',y') in the output image to the coordinate location (x,y) in the input
image by:
(1)
It is not unusual that the input location (x,y), so derived will be nonintegral and will not correspond
exactly to a single pixel in the input image. The situation is depicted below:
Pixel grid locations P, Q, R, and S are integral. Pixel location X = (x,y)T, obtained from the map-
ping equation above, differs from P by fractional amounts s (horizontally) and t (vertically).
Let I(P) be the value of the input image at coordinate P, if P is within the image extent. Otherwise,
let I(P) be constant, where constant is the pixel value passed to the Geometry element. A value of
I(X) must be estimated from I(P), I(Q), I(R), and I(S). From sampling theory, a band width lim-
ited continuous input image can be recovered perfectly (under certain conditions) from its sampled
output by computing the convolution:
I(x,y) is the continuous image, i(m,n) the discrete sampled image, and h(u,v) the impulse response
function for an appropriate low pass filter. Note that both nearest-neighbor and bilinear interpolation
resampling techniques may be cast in this form [ ].
A Gaussian impulse response function has the quality that its Fourier transform has the same bell
curve shape. For certain kinds of images, this provides a better approximation to an ideal low-pass
filter than is represented by either bilinear or nearest-neighbor interpolation. The specific form of
h(u,v) is given by:
The term is called the normalization constant and may be altered using the normalize pa-
rameter. The suggested value for s is 1. Note that all technique parameters must be chosen in con-
cert.
As an example of Gaussian interpolation, assume s = 1 and that point P in the above figure has coor-
dinates (m',n'). Then x = m'+ s and y = n'+ t, and the basic interpolation equation at (x,y) be-
comes:
The contribution from point P in this equation is represented by the summation value for m = m',
n = n'. Identifying this term in Eq (4), the contribution is:
Or:
Similar calculations reveal:
(7)
(8)
(9)
A suggested value for radius is one, that is, only pixels within a distance of one in either the x or y
direction are involved in the calculation. Thus, I(x,y) is given by the sum of Eqs. 6-9. Choosing a
larger radius would bring in more terms.
For computational convenience, a simplified form of Gaussian interpolation is provided. If simple is
true, the impulse-response function of Equation 3a is replaced by:
(3b)
The normalization factor N is defined by normalize. As with true Gaussian interpolation, the radius
parameter is used to determine the number of pixels involved in the computation.
NearestNeighbor
Parameters
modify: CARD8 { FavorDown, FavorUp,
RoundNW, RoundNE,
RoundSW, RoundSE }
(1)
Geometry maps each pixel (x',y') in the output image to the coordinate location (x,y) in the input
image by:
It is not unusual that the input location (x,y), so derived will be nonintegral and will not correspond
exactly to a single pixel in the input image. The situation is depicted below:
Pixel grid locations P, Q, R, and S are integral. Pixel location X = (x,y)T, obtained from the map-
ping equation above, differs from P by fractional amounts s in the x direction and t in the y direc-
tion.
Let I(P) be the value of the input image at coordinate P if P is within the image extent. Otherwise,
let I(P) be constant, where constant is the pixel value passed to the Geometry element. A value of
I(X) must be estimated from I(P), I(Q), I(R), and I(S). In nearest-neighbor sampling, we
simply choose the image value from the discrete location closest to X. Thus,
if s < 1/2, t < 1/2, set I(X) = I(P),
if s > 1/2, t < 1/2, set I(X) = I(Q),
if s > 1/2, t > 1/2, set I(X) = I(R),
if s < 1/2, t > 1/2, set I(X) = I(S).
The behavior on even boundaries (s = 1/2 or t = 1/2) is determined by the modify parameter. If
modify is FavorDown, all less than signs in the above are replaced with less than or equal signs.
Thus, P would win all ties; S and Q would lose to P but win over R; and, R would lose all ties. If
modify is FavorUp , then all greater than signs would be replaced with greater than or equals, and
the opposite behavior would occur.
Four additional options are provided. The RoundNW option will always choose P; RoundNE will al-
ways choose Q; RoundSE will always choose R; and, RoundSW will always choose S. These are not
strictly nearest neighbor algorithms but are available for computational/filtering convenience.
Histogram Shapes
MatchHistogram matches the histogram of a source image to a specific shape represented by a prob-
ability density function. HistogramShape defines various shapes that can be requested.
Flat
Parameters
< none >
Flat specifies that the output image is to have a histogram that approximates a uniform density
(histogram equalization). No additional parameters are required.
Gaussian
Parameters
mean: XieTypFloat
sigma: XieTypFloat
Gaussian specifies that the output image is to have histogram that approximates a Gaussian probabil-
ity density. The supplied parameters are used to generate a Gaussian probability density function
centered around the mean level with a spread specified by sigma:
Hyperbolic
Parameters
constant: XieTypFloat
shape-factor: BOOL
Hyperbolic specifies that the output image is to have histogram that approximates a hyperbolic prob-
ability density.
Constant is used to generate a hyperbolic probability density function:
Shape-factor should be specified as false if the histogram shape represents decreasing values for
higher levels or true if the shape represents increasing values for higher levels.
White Point Adjustment Techniques
WhiteAdjustTechnique defines the white point adjustment techniques that can be used when con-
verting to or from the RGB colorspace. White point correction can be used to ensure that white looks
white, or it can be used to change the overall tint of an image.
None
Parameters
< none >
None specifies that no white point correction is desired.
CIELabShift
Parameters
white-point: XieTypConstant
CIELabShift specifies that white point correction is to be accomplished by adding the white point
displacement to the a*b* plane in the CIELab colorspace. The white-point is specified using
CIEXYZ encodings.
If WhiteAdjustTechnique is used with ConvertFromRGB, white-point specifies the desired white
point of the output data. If WhiteAdjustTechnique is used with ConvertToRGB, white-point speci-
fies the white point of the source data.
A full description of the color matching algorithm is available upon request from author Shelley.
"Color image quantization for frame buffer display", by P. S. Heckbert, Computer Graphics (ACM SIGGRAPH '82 Conf. Proc.),
vol. 16, no. 3, page 297.
CCITT T.4, "Standardization of Group 3 Facsimile Apparatus for Document Transmission"
Image compression generally starts with the least significant pixel in the image (at coordinate 0,0) and proceeds in raster order to
the end of the image. This would be the normal order. Some encoders read pixels in reversed order within each byte (that is, start
reading at bit 7 and proceed down through 0, then 15 through 8, and so on). Specifying normal as false can correct for this situa-
tion upon decode (that is, the bit order within each byte of decoded data is reversed before the data are forwarded to downstream
elements).
CCITT T.6, "Facsimile Coding Schemes and Coding Control Functions for Group 4 Facsimile Apparatus"
ISO DIS 10918-1 "Digital Compression and Coding of Continuous-tone Still Images"
"TIFF Tag Image File Format", revision 6.0, draft 2, by Aldus Corporation
Image compression generally starts with the least significant pixel in the image (at coordinate 0,0) and proceeds in raster order to
the end of the image. This would be the normal order. Some encoders read pixels in reversed order within each byte (that is, start
reading at bit 7 and proceed down through 0, then 15 through 8, and so on). Specifying normal as false can correct for this situa-
tion upon decode (that is, the bit order within each byte of decoded data is reversed before the data are forwarded to downstream
elements).
"Digital Halftoning", by R. A. Ulichney, Cambridge, MA: The MIT Press
"Adaptive algorithm for spatial grey scale", by R. W. Floyd and L. Steinberg, SID Int. Sym. Digest of Tech. Papers, page 36
"An optimum method for two level rendition of continuous-tone pictures", by B. E. Bayer, Proc. IEEE Int. Conf. Commun.,
Conference Record, page 26-11
"Digital Halftoning", by R. A. Ulichney, Cambridge, MA: The MIT Press
CCITT T.4, "Standardization of Group 3 Facsimile Apparatus for Document Transmission"
CCITT T.6 "Facsimile Coding Schemes and Coding Control Functions for Group 4 Facsimile Apparatus"
ISO DIS 10918-1 "Digital Compression and Coding of Continuous-tone Still Images"
"TIFF Tag Image File Format", revision 6.0, draft 2, by Aldus Corporation
A. Jain. Fundamentals of Digital Image Processing. Englewood Cliffs, J.J.: Prentice-Hall, 1989
Techniques A-28
B
Service Class
Full
The full XIE protocol is deemed sufficient to rendering and displaying bitonal, gray-scale, and color
images on an X server. Full XIE encompasses everything in this document.
DIS
The Document Imaging Subsets (DIS) targeted at the viewing of compressed, bitonal documents on
displays that might not otherwise have the resources for the full XIE protocol. DIS provides a mini-
mal set of primitives for manipulating Constrained, SingleBand data and differs from Full XIE in
the following ways:
* Only LUT, Photomap, Photoflo, and Photospace resources are supported.
* ColorList and ROI resources are not supported.
* Only Geometry and Point process elements are supported.
* Restricting processing via a ProcessDomain is not supported.
* TripleBand data is not supported.
* Image data is always Constrained and is limited to 2max-depth levels, where max-depth is the depth
of the deepest DRAWABLE supported by the server.
* The Decode_JPEG-Baseline technique is optional (rather than required).
Typical DIS applications will use relatively simple Photoflos that import image data, apply a geomet-
ric transformation, and export the result to a DRAWABLE for display. Figure B-1 summarizes the im-
port, process, and export elements that are provided in DIS:
Sources Operators Destinations
ImportDrawable Geometry ExportDrawable
ImportDrawablePlane Point ExportDrawablePlane
ImportLUT ExportLUT
ImportClientLUT ExportClientLUT
ImportPhotomap ExportPhotomap
ImportClientPhoto ExportClientPhoto
Figure B-1 DIS sources, operators, and destinations
Service Class Summary
The following tables summarize the service classes to which each item in the XIE protocol belongs.
For some XIE types, where a list of alternative values is defined, some of the alternative values are
required for a particular service class, while others are not. In these cases, the alternative values are
itemized. If all items of a type are required or none are, the type itself is either required or excluded.
Alternative techniques are listed separately in Table B-2.
Table B-1 Types itemized by ServiceClass
Type Full DIS
XieTypAlignment required required
XieTypArithmeticOp required excluded
XieTypColorAllocTechnique required excluded
XieTypColorList required excluded
XieTypCompareOp required excluded
XieTypConstant required required
XieTypConstrainTechnique required excluded
XieTypCovertFromRGBTechnique required excluded
XieTypCovertToRGBTechnique required excluded
XieTypConvolveTechnique required excluded
XieTypDataClass required required
XieValSingleBand required required
XieValTripleBand required excluded
XieTypDataStream required required
XieTypDataType required required
XieTypDecodeTechnique required required
XieTypDitherTechnique required excluded
XieTypEncodeTechnique required required
XieTypExecutable required required
XieTypExportNotify required required
XieTypExportState required required
XieTypFloat required required
XieTypGamutTechnique required excluded
XieTypGeometryTechnique required required
XieTypHistogramData required excluded
XieTypHistogramShape required excluded
XieTypInterleave required required
XieTypLevels required required
XieTypLUT required required
XieTypMathOp required excluded
XieTypMatrix required excluded
XieTypOrientation required required
XieTypPhotoElement required required
XieTypPhotoflo required required
XieTypPhotofloOutcome required required
XieTypPhotofloState required required
XieTypPhotomap required required
XieTypPhotospace required required
XieTypPhototag required required
XieTypProcessDomain required required
XieTypRectangle required excluded
XieTypROI required excluded
Table B-1 Types itemized by ServiceClass (continued)
Type Full DIS
XieTypServiceClass required required
XieValFull required excluded
XieValDIS required required
XieTypTechniqueGroup required required
XieValDefault required required
XieValAll required required
XieValColorAlloc required excluded
XieValConstrain required excluded
XieValConvertFromRGB required excluded
XieValConvertToRGB required excluded
XieValConvolve required excluded
XieValDecode required required
XieValDither required excluded
XieValEncode required required
XieValGamut required excluded
XieValGeometry required required
XieValHistogram required excluded
XieValWhiteAdjust required excluded
XieTypTechniqueRec required required
XieTypTile required excluded
XieTypTripletof required required
XieTypWhiteAdjustTechnique required excluded
Table B-2 Techniques itemized by ServiceClass
Technique Full DIS
XieValColorAlloc_AllocAll optional excluded
XieValColorAlloc_Match optional excluded
XieValColorAlloc_Requantize optional excluded
XieValConstrain_ClipScale required excluded
XieValConstrain_HardClip required excluded
XieValConvertFromRGB_CIELab required excluded
XieValConvertFromRGB_CIEXYZ required excluded
XieValConvertFromRGB_YCbCr required excluded
XieValConvertFromRGB_YCC required excluded
XieValConvertToRGB_CIELab required excluded
XieValConvertToRGB_CIEXYZ required excluded
XieValConvertToRGB_YCbCr required excluded
XieValConvertToRGB_YCC required excluded
XieValConvolve_Constant required excluded
XieValConvolve_Replicate optional excluded
XieValDecode_UncompressedSingle required required
XieValDecode_UncompressedTriple required excluded
XieValDecode_CCITT-G31D required required
XieValDecode_CCITT-G32D required required
XieValDecode_CCITT-G42D required required
XieValDecode_JPEG-Baseline required optional
XieValDecode_JPEG-Lossless optional optional
XieValDecode_TIFF-2 optional optional
XieValDecode_TIFF-PackBits optional optional
XieValDither_ErrorDiffusion optional excluded
XieValDither_Ordered optional excluded
XieValEncode_ServerChoice required required
XieValEncode_UncompressedSingle required required
XieValEncode_UncompressedTriple required excluded
XieValEncode_CCITT-G31D optional optional
XieValEncode_CCITT-G32D optional optional
XieValEncode_CCITT-G42D optional optional
XieValEncode_JPEG-Baseline optional optional
XieValEncode_JPEG-Lossless optional optional
XieValEncode_TIFF-2 optional optional
XieValEncode_TIFF-PackBits optional optional
XieValGamut_None required excluded
XieValGamut_ClipRGB required excluded
XieValGeometry_Antialias required required
XieValGeometry_AntialiasByArea optional optional
XieValGeometry_AntialiasByLowpass optional optional
XieValGeometry_BilinearInterpolation optional optional
XieValGeometry_Gaussian optional optional
XieValGeometry_NearestNeighbor required required
XieValHistogram_Flat required excluded
XieValHistogram_Gaussian required excluded
XieValHistogram_Hyperbolic required excluded
XieValWhiteAdjust_None required excluded
XieValWhiteAdjust_CIELabShift optional excluded
Table B-3 Requests itemized by ServiceClass
Requests Full DIS
XieReqQueryImageExtension required required
XieReqQueryTechniques required required
XieReqCreateColorList required excluded
XieReqDestroyColorList required excluded
XieReqPurgeColorList required excluded
XieReqQueryColorList required excluded
XieReqCreateLUT required required
XieReqDestroyLUT required required
XieReqCreatePhotomap required required
XieReqDestroyPhotomap required required
XieReqQueryPhotomap required required
XieReqCreateROI required excluded
XieReqDestroyROI required excluded
XieReqCreatePhotospace required required
XieReqDestroyPhotospace required required
XieReqExecuteImmediate required required
XieReqCreatePhotoflo required required
XieReqDestroyPhotoflo required required
XieReqExecutePhotoflo required required
XieReqModifyPhotoflo required required
XieReqRedefinePhotoflo required required
XieReqPutClientData required required
XieReqGetClientData required required
XieReqQueryPhotoflo required required
XieReqAwait required required
XieReqAbort required required
Table B-4 Import elements itemized by ServiceClass
Import Element Full DIS
XieFloImportClientLUT required required
XieFloImportClientPhoto required required
XieFloImportClientROI required excluded
XieFloImportDrawable required required
XieFloImportDrawablePlane required required
XieFloImportLUT required required
XieFloImportPhotomap required required
XieFloImportROI required excluded
Table B-5 Process elements itemized by ServiceClass
Process Element Full DIS
XieFloArithmetic required excluded
XieFloBandCombine required excluded
XieFloBandExtract required excluded
XieFloBandSelect required excluded
XieFloBlend required excluded
XieFloCompare required excluded
XieFloConstrain required excluded
XieFloConvertFromIndex required excluded
XieFloConvertFromRGB required excluded
XieFloConvertToIndex required excluded
XieFloConvertToRGB required excluded
XieFloConvolve required excluded
XieFloDither required excluded
XieFloGeometry required required
XieFloLogical required excluded
XieFloMatchHistogram required excluded
XieFloMath required excluded
XieFloPasteUp required excluded
XieFloPoint required required
XieFloUnconstrain required excluded
Table B-6 Export elements itemized by ServiceClass
Export Element Full DIS
XieFloExportClientHistogram required excluded
XieFloExportClientLUT required required
XieFloExportClientPhoto required required
XieFloExportClientROI required excluded
XieFloExportDrawable required required
XieFloExportDrawablePlane required required
XieFloExportLUT required required
XieFloExportPhotomap required required
XieFloExportROI required excluded
Table B-7 Events itemized by ServiceClass
Event Full DIS
XieEvnColorAlloc required excluded
XieEvnDecodeNotify required required
XieEvnExportAvailable required required
XieEvnImportObscured required required
XieEvnPhotofloDone required required
Table B-8 Errors itemized by ServiceClass
Error Full DIS
XieErrColorList required excluded
XieErrLUT required required
XieErrPhotoflo required required
XieErrPhotomap required required
XieErrPhotospace required required
XieErrROI required excluded
XieErrFloAccess required required
XieErrFloAlloc required required
XieErrFloColormap required excluded
XieErrFloColorList required excluded
XieErrFloDomain required required
XieErrFloDrawable required required
XieErrFloElement required required
XieErrFloGC required required
XieErrFloID required required
XieErrFloLength required required
XieErrFloLUT required required
XieErrFloMatch required required
XieErrFloOperator required excluded
XieErrFloPhotomap required required
XieErrFloROI required excluded
XieErrFloSource required required
XieErrFloTechnique required required
XieErrFloValue required required
XieErrFloImplementation required required
almost blank
Service Class B-8
C
Protocol Encodings
Extension Name
# of Bytes Value Description
3 upper-case ASCII string "XIE"
88 X
73 I
69 E
Types
Alignment
# of Bytes Value Description
1 alignment:
1 Alignable
2 Arbitrary
ArithmeticOp
# of Bytes Value Description
1 operator:
1 Add
2 Sub
3 SubRev
4 Mul
5 Div
6 DivRev
7 Min
8 Max
9 Gamma
ColorAllocTechnique
# of Bytes Value Description
2 number:
0 Default
2 ColorAlloc_AllocAll
4 ColorAlloc_Match
6 ColorAlloc_Requantize
ColorList
# of Bytes Value Description
4 CARD32 color-list id (top 3 bits guaranteed to be zero)
CompareOp
# of Bytes Value Description
1 operator:
1 LT
2 LE
3 EQ
4 NE
5 GT
6 GE
Constant
# of Bytes Value Description
4 Float constant[0]
4 Float constant[1]
4 Float constant[2]
ConstrainTechnique
# of Bytes Value Description
2 number:
2 Constrain_ClipScale
4 Constrain_HardClip
ConvertFromRGBTechnique
# of Bytes Value Description
2 number:
2 ConvertFrom_CIELab
4 ConvertFrom_CIEXYZ
6 ConvertFrom_YCbC
8 ConvertFrom_YCC
ConvertToRGBTechnique
# of Bytes Value Description
2 number:
2 ConvertTo_CIELab
4 ConvertTo_CIEXYZ
6 ConvertTo_YCbC
8 ConvertTo_YCC
ConvolveTechnique
# of Bytes Value Description
2 number:
0 Default
2 Convolve_Constant
4 Convolve_Replicate
DataClass
# of Bytes Value Description
1 data-class:
1 SingleBand
2 TripleBand
DataStream
# of Bytes Value Description
n LISTofCARD8 data
DataType
# of Bytes Value Description
1 data-type:
1 Constrained
2 Unconstrained
DecodeTechnique
# of Bytes Value Description
2 number:
2 Decode_UncompressedSingle
3 Decode_UncompressedTriple
4 Decode_CCITT-G31D
6 Decode_CCITT-G32D
8 Decode_CCITT-G42D
10 Decode_JPEG-Baseline
12 Decode_JPEG-Lossless
14 Decode_TIFF-2
16 Decode_TIFF-PackBits
DitherTechnique
# of Bytes Value Description
2 number:
0 Default
2 Dither_ErrorDiffusion
4 Dither_Ordered
EncodeTechnique
# of Bytes Value Description
2 number:
1 Encode_ServerChoice
2 Encode_UncompressedSingle
3 Encode_UncompressedTriple
4 Encode_CCITT-G31D
6 Encode_CCITT-G32D
8 Encode_CCITT-G42D
10 Encode_JPEG-Baseline
12 Encode_JPEG-Lossless
14 Encode_TIFF-2
16 Encode_TIFF-PackBits
Executable
# of Bytes Value Description
4 name-space:
Photospace if immediate Photoflo
0 if stored Photoflo
4 flo-id:
CARD32 if immediate Photoflo
Photoflo if stored Photoflo
ExportNotify
# of Bytes Value Description
1 notify:
1 Disable
2 FirstData
3 NewData
ExportState
# of Bytes Value Description
1 state:
1 ExportDone
2 ExportMore
3 ExportEmpty
4 ExportError
Float
# of Bytes Value Description
4 <32-bits> IEEE single-precision float
GamutTechnique
# of Bytes Value Description
2 number:
0 Default
1 Gamut_None
2 Gamut_ClipRGB
GeometryTechnique
# of Bytes Value Description
2 number:
0 Default
2 Geometry_Antialias
4 Geometry_AntialiasByArea
6 Geometry_AntialiasByLowpass
8 Geometry_BilinearInterpolation
10 Geometry_Gaussian
12 Geometry_NearestNeighbor
HistogramData
# of Bytes Value Description
4 CARD32 value
4 CARD32 count
HistogramShape
# of Bytes Value Description
2 number:
2 Histogram_Flat
4 Histogram_Gaussian
6 Histogram_Hyperbolic
Interleave
# of Bytes Value Description
1 interleave:
1 BandByPixel
2 BandByPlane
Levels
# of Bytes Value Description
4 CARD32 levels[0]
4 CARD32 levels[1]
4 CARD32 levels[2]
LUT
# of Bytes Value Description
4 CARD32 lut id (top 3 bits guaranteed to be zero)
MathOp
# of Bytes Value Description
1 operator:
1 Exp
2 Ln
3 Log2
4 Log10
5 Square
6 Sqrt
Matrix
# of Bytes Value Description
4 Float matrix[0,0]
4 Float matrix[0,1]
4 Float matrix[0,2]
4 Float matrix[1,0]
4 Float matrix[1,1]
4 Float matrix[1,2]
4 Float matrix[2,0]
4 Float matrix[2,1]
4 Float matrix[2,2]
Orientation
# of Bytes Value Description
1 order:
1 LSFirst
2 MSFirst
PhotoElement
Refer to the individual Import, Process, and Export encodings.
Photoflo
# of Bytes Value Description
4 CARD32 stored photoflo id (top 3 bits guaranteed to be zero)
PhotofloOutcome
# of Bytes Value Description
1 outcome:
1 FloSuccess
2 FloAbort
3 FloError
PhotofloState
# of Bytes Value Description
1 state:
1 Inactive
2 Active
3 Nonexistent
Photomap
# of Bytes Value Description
4 CARD32 photomap id (top 3 bits guaranteed to be zero)
Photospace
# of Bytes Value Description
4 CARD32 photospace id (top 3 bits guaranteed to be zero)
Phototag
# of Bytes Value Description
2 CARD16 phototag (index within PhotoElement list)
ProcessDomain
# of Bytes Value Description
4 INT32 offset-x
4 INT32 offset-y
2 Phototag domain
Rectangle
# of Bytes Value Description
4 INT32 x
4 INT32 y
4 CARD32 width
4 CARD32 height
ROI
# of Bytes Value Description
4 CARD32 roi id (top 3 bits guaranteed to be zero)
ServiceClass
# of Bytes Value Description
1 class:
1 Full
2 DIS
TechniqueGroup
# of Bytes Value Description
1 group:
0 Default
1 All
2 ColorAlloc
4 Constrain
6 ConvertFromRGB
8 ConvertToRGB
10 Convolve
12 Decode
14 Dither
16 Encode
18 Gamut
20 Geometry
22 Histogram
24 WhiteAdjust
TechniqueRec
# of Bytes Value Description
1 BOOL needs-parameters
1 TechniqueGroup group
2 CARD16 number
1 CARD8 speed (0: slowest, 255: fastest)
1 n length of name
2 unused
n LISTofCARD8 name (ASCII string)
p unused, p=pad(n)
Tile
# of Bytes Value Description
2 Phototag src
2 unused
4 INT32 dst-x
4 INT32 dst-y
Tripletoftype
# of Bytes Value Description
size of type <size of type bytes> value[0]
size of type <size of type bytes> value[1]
size of type <size of type bytes> value[2]
WhiteAdjustTechnique
# of Bytes Value Description
2 number:
0 Default
1 WhiteAdjust_None
2 WhiteAdjust_CIELabShift
Requests and Replies
QueryImageExtension request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 1 XIE minor opcode
2 2 request length
2 CARD16 client-major-version
2 CARD16 client-minor-version
QueryImageExtension reply
# of Bytes Value Description
1 1 reply
1 unused
2 CARD16 sequence number
4 n reply length (length of constrained-levels)
2 CARD16 server-major-version
2 CARD16 server-minor-version
1 ServiceClass service-class
1 Alignment alignment
2 CARD16 unconstrained-mantissa
4 INT32 unconstrained-max-exp
4 INT32 unconstrained-min-exp
8 unused
4n LISTofCARD32 constrained-levels
QueryTechniques request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 2 XIE minor opcode
2 2 request length
1 TechniqueGroup technique-group
3 unused
QueryTechniques reply
# of Bytes Value Description
1 1 reply
1 unused
2 CARD16 sequence number
4 n/4 reply length
2 CARD16 number of techniques
22 unused
n LISTofTechniqueRec techniques
CreateColorList request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 3 XIE minor opcode
2 2 request length
4 ColorList color-list
DestroyColorList request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 4 XIE minor opcode
2 2 request length
4 ColorList color-list
PurgeColorList request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 5 XIE minor opcode
2 2 request length
4 ColorList color-list
QueryColorList request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 6 XIE minor opcode
2 2 request length
4 ColorList color-list
QueryColorList reply
# of Bytes Value Description
1 1 reply
1 unused
2 CARD16 sequence number
4 n reply length (number of colors)
4 COLORMAP colormap
20 unused
4n LISTofCARD32 list of colors
CreateLUT request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 7 XIE minor opcode
2 2 request length
4 LUT lut
DestroyLUT request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 8 XIE minor opcode
2 2 request length
4 LUT lut
CreatePhotomap request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 9 XIE minor opcode
2 2 request length
4 Photomap photomap
DestroyPhotomap request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 10 XIE minor opcode
2 2 request length
4 Photomap photomap
QueryPhotomap request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 11 XIE minor opcode
2 2 request length
4 Photomap photomap
QueryPhotomap reply
# of Bytes Value Description
1 1 reply
1 BOOL populated
2 CARD16 sequence number
4 4 reply length
1 DataClass data-class
1 DataType data-type
2 DecodeTechnique
12 TripletofCARD32 width
12 TripletofCARD32 height
12 Levels levels
CreateROI request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 12 XIE minor opcode
2 2 request length
4 ROI roi
DestroyROI request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 13 XIE minor opcode
2 2 request length
4 ROI roi
CreatePhotospace request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 14 XIE minor opcode
2 2 request length
4 Photospace name-space
DestroyPhotospace request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 15 XIE minor opcode
2 2 request length
4 Photospace name-space
ExecuteImmediate request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 16 XIE minor opcode
2 4+n/4 request length
8 Executable instance
2 CARD16 number of elements in element-list
1 BOOL notify
1 unused
n LISTofPhotoElement element-list
CreatePhotoflo request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 17 XIE minor opcode
2 3+n/4 request length
4 Photoflo photoflo
2 CARD16 number of elements in element-list
2 unused
n LISTofPhotoElement element-list
DestroyPhotoflo request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 18 XIE minor opcode
2 2 request length
4 Photoflo photoflo
ExecutePhotoflo request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 19 XIE minor opcode
2 3 request length
4 Photoflo photoflo
1 BOOL notify
3 unused
ModifyPhotoflo request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 20 XIE minor opcode
2 3+n/4 request length
4 Photoflo photoflo
2 Phototag start
2 CARD16 number of elements in element-list
n LISTofPhotoElement element-list
RedefinePhotoflo request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 21 XIE minor opcode
2 3+n/4 request length
4 Photoflo photoflo
2 CARD16 number of elements in element-list
2 unused
n LISTofPhotoElement element-list
PutClientData request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 22 XIE minor opcode
2 5+(n+p)/4 request length
8 Executable instance
2 Phototag element
1 BOOL final
1 CARD8 band-number
4 n byte-count (length of data in bytes)
n LISTofCARD8 data
p unused, p=pad(n)
GetClientData request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 23 XIE minor opcode
2 5 request length
8 Executable instance
4 CARD32 max-bytes
2 Phototag element
1 BOOL terminate
1 CARD8 band-number
GetClientData reply
# of Bytes Value Description
1 1 reply
1 ExportState new-state
2 CARD16 sequence number
4 (n+p)/4 reply length
4 n byte-count (length of data in bytes)
20 unused
n LISTofCARD8 data
p unused, p=pad(n)
QueryPhotoflo request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 24 XIE minor opcode
2 3 request length
8 Executable instance
QueryPhotoflo reply
# of Bytes Value Description
1 1 reply
1 PhotofloState state
2 CARD16 sequence number
4 (e+a)/2+(ep+ap)/4 reply length
2 e data-expected count
2 a data-available count
20 unused
2e LISTofPhototag data-expected
ep unused, ep=pad(e)
2a LISTofPhototag data-available
ap unused, ap=pad(a)
Await request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 25 XIE minor opcode
2 3 request length
8 Executable instance
Abort request
# of Bytes Value Description
1 CARD8 XIE major opcode
1 26 XIE minor opcode
2 3 request length
8 Executable instance
Import Elements
ImportClientLUT
# of Bytes Value Description
2 1 element type
2 8 element length
1 DataClass class
1 Orientation band-order
2 unused
12 TripletofCARD32 length
12 Levels levels
ImportClientPhoto
# of Bytes Value Description
2 2 element type
2 12+n element length
1 BOOL notify
1 DataClass class
2 unused
12 TripletofCARD32 width
12 TripletofCARD32 height
12 Levels levels
2 DecodeTechnique decode
2 n length of decode-params
4n <technique-dependent> decode-params
ImportClientROI
# of Bytes Value Description
2 3 element type
2 2 element length
4 CARD32 rectangles
ImportDrawable
# of Bytes Value Description
2 4 element type
2 6 element length
4 DRAWABLE drawable
2 INT16 src-x
2 INT16 src-y
2 CARD16 width
2 CARD16 height
4 CARD32 fill
1 BOOL notify
3 unused
ImportDrawablePlane
# of Bytes Value Description
2 5 element type
2 7 element length
4 DRAWABLE drawable
2 INT16 src-x
2 INT16 src-y
2 CARD16 width
2 CARD16 height
4 CARD32 fill
4 CARD32 bit-plane
1 BOOL notify
3 unused
ImportLUT
# of Bytes Value Description
2 6 element type
2 2 element length
4 LUT lut
ImportPhotomap
# of Bytes Value Description
2 7 element type
2 3 element length
4 Photomap photomap
1 BOOL notify
3 unused
ImportROI
# of Bytes Value Description
2 8 element type
2 2 element length
4 ROI roi
Process Elements
Arithmetic
# of Bytes Value Description
2 9 element type
2 8 element length
2 Phototag src-1
2 Phototag src-2
10 ProcessDomain domain
1 ArithmeticOp operator
1 CARD8 band-mask
12 Constant constant
BandCombine
# of Bytes Value Description
2 10 element type
2 3 element length
2 Phototag src-1
2 Phototag src-2
2 Phototag src-3
2 unused
BandExtract
# of Bytes Value Description
2 11 element type
2 7 element length
2 Phototag src
2 unused
4 CARD32 levels
4 Float bias
12 Constant coefficients
BandSelect
# of Bytes Value Description
2 12 element type
2 2 element length
2 Phototag src
1 CARD8 band-number
1 unused
Blend
# of Bytes Value Description
2 13 element type
2 10 element length
2 Phototag src-1
2 Phototag src-2
2 Phototag alpha
2 unused
10 ProcessDomain domain
1 CARD8 band-mask
1 unused
12 Constant constant
4 Float alpha-const
Compare
# of Bytes Value Description
2 14 element type
2 9 element length
2 Phototag src-1
2 Phototag src-2
10 ProcessDomain domain
1 CompareOp operator
1 BOOL combine
12 Constant constant
1 CARD8 band-mask
3 unused
Constrain
# of Bytes Value Description
2 15 element type
2 6+n element length
2 Phototag src
2 unused
12 Levels levels
2 ConstrainTechnique constrain
2 n length of constrain-params
4n <technique-dependent> constrain-params
ConvertFromIndex
# of Bytes Value Description
2 16 element type
2 3 element length
2 Phototag src
1 DataClass class
1 CARD8 precision (valid range 1..16)
4 COLORMAP colormap
ConvertFromRGB
# of Bytes Value Description
2 17 element type
2 3+n element length
2 Phototag src
2 unused
2 ConvertFromRGBTechnique convert
2 n length of convert-params
4n <technique-dependent> convert-params
ConvertToIndex
# of Bytes Value Description
2 18 element type
2 5+n element length
2 Phototag src
1 BOOL notify
1 unused
4 COLORMAP colormap
4 ColorList color-list
2 ColorAllocTechnique color-alloc
2 n length of color-alloc-params
4n <technique-dependent> color-alloc-params
ConvertToRGB
# of Bytes Value Description
2 19 element type
2 3+n element length
2 Phototag src
2 unused
2 ConvertToRGBTechnique convert
2 n length of convert-params
4n <technique-dependent> convert-params
Convolve
# of Bytes Value Description
2 20 element type
2 6+n2+m element length
2 Phototag src
2 unused
10 ProcessDomain domain
1 CARD8 band-mask
1 n kernel-size
2 ConvolveTechnique convolve
2 m length of convolve-params
4n2 LISTofFloat kernel
4m <technique-dependent> convolve-params
Dither
# of Bytes Value Description
2 21 element type
2 6+n element length
2 Phototag src
1 CARD8 band-mask
1 unused
12 Levels levels
2 DitherTechnique dither
2 n length of dither-params
4n <technique-dependent> dither-params
Geometry
# of Bytes Value Description
2 22 element type
2 14+n element length
2 Phototag src
1 CARD8 band-mask
1 unused
4 CARD32 width
4 CARD32 height
4 Float coefficients: a
4 Float coefficients: b
4 Float coefficients: c
4 Float coefficients: d
4 Float coefficients: tx
4 Float coefficients: ty
12 Constant constant
2 GeometryTechnique sample
2 n length of sample-params
4n <technique-dependent> sample-params
Logical
# of Bytes Value Description
2 23 element type
2 8 element length
2 Phototag src-1
2 Phototag src-2
10 ProcessDomain domain
1 GCfunction* operator
1 CARD8 band-mask
12 Constant constant
(* see note on page 7-20)
MatchHistogram
# of Bytes Value Description
2 24 element type
2 6+n element length
2 Phototag src
2 unused
10 ProcessDomain domain
2 unused
2 HistogramShape shape
2 n length of shape-params
4n <technique-dependent> shape-params
Math
# of Bytes Value Description
2 25 element type
2 5 element length
2 Phototag src
2 unused
10 ProcessDomain domain
1 MathOp operator
1 CARD8 band-mask
PasteUp
# of Bytes Value Description
2 26 element type
2 7+3n element length
2 n number of tiles
2 unused
4 CARD32 width
4 CARD32 height
12 Constant constant
12n LISTofTile tiles
Point
# of Bytes Value Description
2 27 element type
2 5 element length
2 Phototag src
2 Phototag lut
10 ProcessDomain domain
1 CARD8 band-mask
1 unused
Unconstrain
# of Bytes Value Description
2 28 element type
2 2 element length
2 Phototag src
2 unused
Export Elements
ExportClientHistogram
# of Bytes Value Description
2 29 element type
2 5 element length
2 Phototag src
1 ExportNotify notify
1 unused
10 ProcessDomain domain
2 unused
ExportClientLUT
# of Bytes Value Description
2 30 element type
2 8 element length
2 Phototag src
1 ExportNotify notify
1 Orientation band-order
12 TripletofCARD32 start
12 TripletofCARD32 length
ExportClientPhoto
# of Bytes Value Description
2 31 element type
2 3+n element length
2 Phototag src
1 ExportNotify notify
1 unused
2 EncodeTechnique encode (any except Encode_ServerChoice)
2 n length of encode-params
4n <technique-dependent> encode-params
ExportClientROI
# of Bytes Value Description
2 32 element type
2 2 element length
2 Phototag src
1 ExportNotify notify
1 unused
ExportDrawable
# of Bytes Value Description
2 33 element type
2 5 element length
2 Phototag src
2 INT16 dst-x
2 INT16 dst-y
2 unused
4 DRAWABLE drawable
4 GCONTEXT gc
ExportDrawablePlane
# of Bytes Value Description
2 34 element type
2 5 element length
2 Phototag src
2 INT16 dst-x
2 INT16 dst-y
2 unused
4 DRAWABLE drawable
4 GCONTEXT gc
ExportLUT
# of Bytes Value Description
2 35 element type
2 6 element length
2 Phototag src
1 BOOL merge
1 unused
4 LUT lut
12 TripletofCARD32 start
ExportPhotomap
# of Bytes Value Description
2 36 element type
2 4+n element length
2 Phototag src
2 unused
4 Photomap photomap
2 EncodeTechnique encode
2 n length of encode-params
4n <technique-dependent> encode-params
ExportROI
# of Bytes Value Description
2 37 element type
2 3 element length
2 Phototag src
2 unused
4 ROI roi
Technique Parameters
ColorAlloc
Default
# of Bytes Value Description
0 <no parameters>
AllocAll
# of Bytes Value Description
4 CARD32 fill
Match
# of Bytes Value Description
4 Float match-limit
4 Float gray-limit
Requantize
# of Bytes Value Description
4 CARD32 max-cells
Constrain
ClipScale
# of Bytes Value Description
12 Constant input-low
12 Constant input-high
12 Levels output-low
12 Levels output - high
HardClip
# of Bytes Value Description
0 <no parameters>
ConvertFromRGB
CIELab
# of Bytes Value Description
36 Matrix matrix
2 WhiteAdjustTechnique white-adjust
2 w length of white-params
4w <technique-dependent> white-params
CIEXYZ
# of Bytes Value Description
36 Matrix matrix
2 WhiteAdjustTechnique white-adjust
2 w length of white-params
4w <technique-dependent> white-params
YCbCr
# of Bytes Value Description
12 Levels levels
12 Constant luma { red, green, blue }
12 Constant bias
YCC
# of Bytes Value Description
12 Levels levels
12 Constant luma { red, green, blue }
4 Float scale
ConvertToRGB
CIELab
# of Bytes Value Description
36 Matrix matrix
2 WhiteAdjustTechnique white-adjust
2 w length of white-params
2 GamutTechnique gamut-compress
2 g length of gamut-params
4w <technique-dependent> white-params
4g <technique-dependent> gamut-params
CIEXYZ
# of Bytes Value Description
36 Matrix matrix
2 WhiteAdjustTechnique white-adjust
2 w length of white-params
2 GamutTechnique gamut-compress
2 g length of gamut-params
4w <technique-dependent> white-params
4g <technique-dependent> gamut-params
YCbCr
# of Bytes Value Description
12 Levels levels
12 Constant luma { red, green, blue }
12 Constant bias
2 GamutTechnique gamut-compress
2 g length of gamut-params
4g <technique-dependent> gamut-params
YCC
# of Bytes Value Description
12 Levels levels
12 Constant luma { red, green, blue }
4 Float scale
2 GamutTechnique gamut-compress
2 g length of gamut-params
4g <technique-dependent> gamut-params
Convolve
Default
# of Bytes Value Description
0 <no parameters>
Constant
# of Bytes Value Description
12 Constant constant
Replicate
# of Bytes Value Description
0 <no parameters>
Decode
UncompressedSingle
# of Bytes Value Description
1 Orientation fill-order
1 Orientation pixel-order
1 CARD8 pixel-stride
1 CARD8 left-pad
1 CARD8 scanline-pad
3 unused
UncompressedTriple
# of Bytes Value Description
3 TripletofCARD8 left-pad
1 Orientation fill-order
3 TripletofCARD8 pixel-stride
1 Orientation pixel-order
3 TripletofCARD8 scanline-pad
1 Orientation band-order
1 Interleave interleave
3 unused
CITT-G31D
# of Bytes Value Description
1 Orientation encoded-order
1 BOOL normal
1 BOOL radiometric
1 unused
CCITT-G32D
# of Bytes Value Description
1 Orientation encoded-order
1 BOOL normal
1 BOOL radiometric
1 unused
CCITT-G42D
# of Bytes Value Description
1 Orientation encoded-order
1 BOOL normal
1 BOOL radiometric
1 unused
JPEG-Baseline
# of Bytes Value Description
1 Interleave interleave
1 Orientation band-order
1 BOOL up-sample
1 unused
JPEG-Lossless
# of Bytes Value Description
1 Interleave interleave
1 Orientation band-order
2 unused
TIFF-2
# of Bytes Value Description
1 Orientation encoded-order
1 BOOL normal
1 BOOL radiometric
1 unused
TIFF-PackBits
# of Bytes Value Description
1 Orientation encoded-order
1 BOOL normal
2 unused
Dither
Default
# of Bytes Value Description
0 <no parameters>
ErrorDiffusion
# of Bytes Value Description
0 <no parameters>
Ordered
# of Bytes Value Description
1 CARD8 threshold-order
3 unused
Encode
ServerChoice
# of Bytes Value Description
1 CARD8 preference:
0 PreferDefault
1 PreferSpace
2 PreferTime
3 unused
UncompressedSingle
# of Bytes Value Description
1 Orientation fill-order
1 Orientation pixel-order
1 CARD8 pixel-stride
1 CARD8 scanline-pad
UncompressedTriple
# of Bytes Value Description
3 TripletofCARD8 pixel-stride
1 Orientation pixel-order
3 TripletofCARD8 scanline-pad
1 Orientation fill-order
1 Orientation band-order
1 Interleave interleave
2 unused
CCITT-G31D
# of Bytes Value Description
1 Orientation encoded-order
1 BOOL align-eol
1 BOOL radiometric
1 unused
CCITT-G32D
# of Bytes Value Description
1 Orientation encoded-order
1 BOOL align-eol
1 BOOL radiometric
1 BOOL uncompressed
4 CARD32 k-factor
CCITT-G42D
# of Bytes Value Description
1 Orientation encoded-order
1 BOOL radiometric
1 BOOL uncompressed
1 unused
JPEG-Baseline
# of Bytes Value Description
1 Interleave interleave
1 Orientation band-order
3 TripletofCARD8 horizontal-samples[0..2]
3 TripletofCARD8 vertical-samples[0..2]
2 q length of q-table (multiple of 4)
2 a length of ac-table (multiple of 4)
2 d length of dc-table (multiple of 4)
2 unused
q LISTofCARD8 q-table
a LISTofCARD8 ac-table
d LISTofCARD8 dc-table
JPEG-Lossless
# of Bytes Value Description
1 Interleave interleave
1 Orientation band-order
2 t length of table (multiple of 4)
3 TripletofCARD8 predictor[0..2]:
0 PredictorNone
1 PredictorA
2 PredictorB
3 PredictorC
4 PredictorABC
5 PredictorABC2
6 PredictorBAC2
7 PredictorAB2
1 unused
t LISTofCARD8 table
TIFF-2
# of Bytes Value Description
1 Orientation encoded-order
1 BOOL radiometric
2 unused
TIFF-PackBits
# of Bytes Value Description
1 Orientation encoded-order
3 unused
Gamut
Default
# of Bytes Value Description
0 <no parameters>
None
# of Bytes Value Description
0 <no parameters>
ClipRGB
# of Bytes Value Description
0 <no parameters>
Geometry
Default
# of Bytes Value Description
0 <no parameters>
Antialias
# of Bytes Value Description
0 <no parameters>
AntialiasByArea
# of Bytes Value Description
2 INT16 simple
2 unused
AntialiasByLowpass
# of Bytes Value Description
2 INT16 kernel-size
2 unused
BilinearInterpolation
# of Bytes Value Description
0 <no parameters>
Gaussian
# of Bytes Value Description
1 CARD8 radius
1 BOOL simple
2 unused
4 Float sigma
4 Float normalize
NearestNeighbor
# of Bytes Value Description
1 CARD8 modify:
1 FavorDown
2 FavorUp
3 RoundNW
4 RoundNE
5 RoundSE
6 RoundSW
3 unused
Histogram
Flat
# of Bytes Value Description
0 <no parameters>
Gaussian
# of Bytes Value Description
4 Float mean
4 Float sigma
Hyperbolic
# of Bytes Value Description
1 BOOL shape-factor
3 unused
4 Float constant
WhiteAdjust
Default
# of Bytes Value Description
0 <no parameters>
None
# of Bytes Value Description
0 <no parameters>
CIELabShift
# of Bytes Value Description
12 Constant white-point
Events
ColorAlloc
# of Bytes Value Description
1 0 XIE event code: ColorAlloc
1 unused
2 CARD16 sequence-number
4 TIMESTAMP time
8 Executable instance
2 Phototag src
2 type:
18 ConvertToIndex
4 ColorList color-list
2 ColorAllocTechnique color-alloc technique
2 unused
4 CARD32 color-alloc specific data
DecodeNotify
# of Bytes Value Description
1 1 XIE event code: DecodeNotify
1 CARD8 band-number
2 CARD16 sequence-number
4 TIMESTAMP time
8 Executable instance
2 Phototag src
2 type:
2 ImportClientPhoto
7 ImportPhotomap
2 DecodeTechnique decode technique
1 BOOL aborted
1 unused
4 CARD32 data-width
4 CARD32 data-height
ExportAvailable
# of Bytes Value Description
1 2 XIE event code: ExportAvailable
1 CARD8 band-number
2 CARD16 sequence-number
4 TIMESTAMP time
8 Executable instance
2 Phototag src
2 type:
29 ExportClientHistogram
30 ExportClientLUT
31 ExportClientPhoto
32 ExportClientROI
12 TripletofCARD32 data[0..2]
ImportObscured
# of Bytes Value Description
1 3 XIE event code: ImportObscured
1 unused
2 CARD16 sequence-number
4 TIMESTAMP time
8 Executable instance
2 Phototag src
2 type:
4 ImportDrawable
5 ImportDrawablePlane
4 WINDOW window
2 INT16 x
2 INT16 y
2 CARD16 width
2 CARD16 height
PhotofloDone
# of Bytes Value Description
1 4 XIE event code: PhotofloDone
1 PhotofloOutcome outcome
2 CARD16 sequence-number
4 TIMESTAMP time
8 Executable instance
16 unused
Errors
ColorList
# of Bytes Value Description
1 0 Error
1 0 XIE error code: ColorList
2 CARD16 sequence-number
4 ColorList color-list id
2 CARD16 minor-opcode
1 CARD8 major-opcode
21 unused
LUT
# of Bytes Value Description
1 0 Error
1 1 XIE error code: LUT
2 CARD16 sequence-number
4 LUT lut id
2 CARD16 minor-opcode
1 CARD8 major-opcode
21 unused
Photoflo
# of Bytes Value Description
1 0 Error
1 2 XIE error code: Photoflo
2 CARD16 sequence-number
4 Photoflo photoflo id
2 CARD16 minor-opcode
1 CARD8 major-opcode
21 unused
Photomap
# of Bytes Value Description
1 0 Error
1 3 XIE error code: Photomap
2 CARD16 sequence-number
4 Photomap photomap id
2 CARD16 minor-opcode
1 CARD8 major-opcode
21 unused
Photospace
# of Bytes Value Description
1 0 Error
1 4 XIE error code: Photospace
2 CARD16 sequence-number
4 Photospace photospace id
2 CARD16 minor-opcode
1 CARD8 major-opcode
21 unused
ROI
# of Bytes Value Description
1 0 Error
1 5 XIE error code: ROI
2 CARD16 sequence-number
4 ROI roi id
2 CARD16 minor-opcode
1 CARD8 major-opcode
21 unused
FloAccess
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 1 flo-error-code: FloAccess
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
12 unused
FloAlloc
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 2 flo-error-code: FloAlloc
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
12 unused
FloColormap
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 3 flo-error-code: FloColormap
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
4 COLORMAP colormap id
8 unused
FloColorList
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 4 flo-error-code: FloColorList
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
4 ColorList color-list id
8 unused
FloDomain
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 5 flo-error-code: FloDomain
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
2 Phototag domain source
10 unused
FloDrawable
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 6 flo-error-code: FloDrawable
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
4 DRAWABLE drawable id
8 unused
FloElement
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 7 flo-error-code: FloElement
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
12 unused
FloGC
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 8 flo-error-code: FloGC
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
4 GCONTEXT gc id
8 unused
FloID
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 9 flo-error-code: FloID
4 CARD32 executable name-space
16 unused
FloLength
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 10 flo-error-code: FloLength
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
12 unused
FloLUT
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 11 flo-error-code: FloLUT
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
4 LUT lut id
8 unused
FloMatch
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 12 flo-error-code: FloMatch
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
12 unused
FloOperator
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 13 flo-error-code: FloOperator
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
1 CARD8 operator
11 unused
FloPhotomap
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 14 flo-error-code: FloPhotomap
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
4 Photomap photomap id
8 unused
FloROI
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 15 flo-error-code: FloROI
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
4 ROI roi id
8 unused
FloSource
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 16 flo-error-code: FloSource
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
12 unused
FloTechnique
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 17 flo-error-code: FloTechnique
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
2 CARD16 technique-number
2 CARD16 length of tech-params that were supplied
1 TechniqueGroup technique-group
7 unused
FloValue
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 18 flo-error-code: FloValue
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
4 <32-bits> bad-value
8 unused
FloImplementation
# of Bytes Value Description
1 0 Error
1 6 XIE error code: Flo...
2 CARD16 sequence-number
4 CARD32 executable flo-id
2 CARD16 minor-opcode
1 CARD8 major-opcode
1 19 flo-error-code: FloImplementation
4 CARD32 executable name-space
2 Phototag phototag
2 CARD16 type
12 unused
Protocol Endings C-40
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