/* * ppmdiff.c - Mark differences in two PPM files * * Written 2010 by Werner Almesberger * Copyright 2010 Werner Almesberger * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. */ #include #include #include #include #include static uint8_t a_only[3] = { 255, 0, 0 }; static uint8_t b_only[3] = { 0, 255, 0 }; static uint8_t both[3] = { 220, 220, 220 }; static uint8_t frame[3] = { 0, 0, 255 }; static uint8_t frame_fill[3] = { 255, 255, 200 }; static int frame_dist = 40; static int frame_width = 2; static uint8_t *load_ppm(const char *name, int *x, int *y) { FILE *file; char line[100]; int this_x, this_y, depth; int n; uint8_t *img; file = fopen(name, "r"); if (!file) { perror(name); exit(1); } if (!fgets(line, sizeof(line), file)) { fprintf(stderr, "can't read file type\n"); exit(1); } if (strcmp(line, "P6\n")) { fprintf(stderr, "file type must be P6, not %s", line); exit(1); } if (!fgets(line, sizeof(line), file)) { fprintf(stderr, "can't read resolution\n"); exit(1); } if (sscanf(line, "%d %d", &this_x, &this_y) != 2) { fprintf(stderr, "can't parse resolution: %s", line); exit(1); } if (*x || *y) { if (*x != this_x || *y != this_y) { fprintf(stderr, "resolution changed from %dx%d to %dx%d\n", *x, *y, this_x, this_y); exit(1); } } else { *x = this_x; *y = this_y; } if (!fgets(line, sizeof(line), file)) { fprintf(stderr, "can't read depth\n"); exit(1); } if (sscanf(line, "%d", &depth) != 1) { fprintf(stderr, "can't parse depth: %s", line); exit(1); } if (depth != 255) { fprintf(stderr, "depth must be 255, not %d\n", depth); exit(1); } n = *x**y*3; img = malloc(n); if (!img) { perror("malloc"); exit(1); } if (fread(img, 1, n, file) != n) { fprintf(stderr, "can't read %d bytes\n", n); exit(1); } fclose(file); return img; } static struct area { int x0, y0, x1, y1; struct area *next; } *areas = NULL; static void add_area(struct area **root, int x0, int y0, int x1, int y1) { while (*root) { struct area *area = *root; if (area->x0 > x1 || area->y0 > y1 || area->x1 < x0 || area->y1 < y0) { root = &(*root)->next; continue; } x0 = x0 < area->x0 ? x0 : area->x0; y0 = y0 < area->y0 ? y0 : area->y0; x1 = x1 > area->x1 ? x1 : area->x1; y1 = y1 > area->y1 ? y1 : area->y1; *root = area->next; free(area); add_area(&areas, x0, y0, x1, y1); return; } *root = malloc(sizeof(**root)); if (!*root) { perror("malloc"); exit(1); } (*root)->x0 = x0; (*root)->y0 = y0; (*root)->x1 = x1; (*root)->y1 = y1; (*root)->next = NULL; } static void change(int x, int y) { add_area(&areas, x-frame_dist, y-frame_dist, x+frame_dist, y+frame_dist); } static void set_pixel(uint8_t *p, const uint8_t *color, const uint8_t *value) { double f; int i; f = (255-(value[0] | value[1] | value[2]))/255.0; for (i = 0; i != 3; i++) p[i] = 255-(255-color[i])*f; } static uint8_t *diff(const uint8_t *a, const uint8_t *b, int xres, int yres) { uint8_t *res, *p; int x, y; int has_a, has_b; res = p = malloc(xres*yres*3); if (!res) { perror("malloc"); exit(1); } for (y = 0; y != yres; y++) for (x = 0; x != xres; x++) { has_a = (a[0] & a[1] & a[2]) != 255; has_b = (b[0] & b[1] & b[2]) != 255; if (has_a && has_b) { set_pixel(p, both, b); } else if (has_a) { set_pixel(p, a_only, a); change(x, y); } else if (has_b) { set_pixel(p, b_only, b); change(x, y); } else { memset(p, 255, 3); // memcpy(p, "\0\0\xff", 3); } a += 3; b += 3; p += 3; } return res; } static void shadow_diff(const uint8_t *a, const uint8_t *b, int xres, int yres) { int x, y; for (y = 0; y != yres; y++) for (x = 0; x != xres; x++) { if (memcmp(a, b, 3)) change(x, y); a += 3; b += 3; } } static void point(uint8_t *img, int x, int y, int xres, int yres) { uint8_t *p; if (x < 0 || y < 0 || x >= xres || y >= yres) return; p = img+(y*xres+x)*3; if ((p[0] & p[1] & p[2]) != 255) return; memcpy(p, frame, 3); } static void hline(uint8_t *img, int x0, int x1, int y, int xres, int yres) { int x; for (x = x0; x <= x1; x++) point(img, x, y, xres, yres); } static void vline(uint8_t *img, int y0, int y1, int x, int xres, int yres) { int y; for (y = y0; y <= y1; y++) point(img, x, y, xres, yres); } static void fill(uint8_t *img, int x0, int y0, int x1, int y1, int xres, int yres) { int x, y; uint8_t *p; for (y = y0; y <= y1; y++) { if (y < 0 || y >= yres) continue; p = img+(xres*y+x0)*3; for (x = x0; x <= x1; x++) { if (x >= 0 && x < xres && (p[0] & p[1] & p[2]) == 255) memcpy(p, frame_fill, 3); p += 3; } } } static void mark_areas(uint8_t *img, int x, int y) { const struct area *area; int r1 = 0, r2 = 0, i; if (frame_width) { r1 = (frame_width-1)/2; r2 = (frame_width-1)-r1; } for (area = areas; area; area = area->next) { if (frame_width) for (i = -r1; i <= r2; i++) { hline(img, area->x0-r1, area->x1+r2, area->y0+i, x, y); hline(img, area->x0-r1, area->x1+r2, area->y1+i, x, y); vline(img, area->y0+r1, area->y1-r2, area->x0+i, x, y); vline(img, area->y0+r1, area->y1-r2, area->x1+i, x, y); } fill(img, area->x0+r1, area->y0+r1, area->x1-r2, area->y1-r2, x, y); } } static void usage(const char *name) { fprintf(stderr, "usage: %s [-f] [-a color] [-b color] [-c color] [-d pixels]\n" "%6s %*s [-m color] [-n color] [-w pixels] file_a.ppm file_b.ppm\n\n" "%6s %*s [file_a'.ppm file_b'.ppm] [out.ppm]\n\n" " file_a.ppm and file_b.ppm are two input images\n" " file_a'.ppm and file_b'.ppm if present, are searched for changes as well\n" " out.ppm output file (default: standard output)\n\n" " -f generate output (and return success) even if there is no change\n" " -a color color of items only in image A\n" " -b color color of items only in image B\n" " -c color color of items in both images\n" " -d pixels distance between change and marker box. 0 disables markers.\n" " -m color color of the frame of the marker box.\n" " -n color color of the background of the marker box\n" " -w pixels width of the frame of the marker box. 0 disables frames.\n\n" " color is specified as R,B,G with each component as a floating-point\n" " value from 0 to 1. E.g., 1,1,1 is white.\n\n" " The images are expected to have dark colors on a perfectly white\n" " background.\n" , name, "", (int) strlen(name), "", "", (int) strlen(name), ""); exit(1); } static void parse_color(uint8_t *c, const char *s, const char *name) { float r, g, b; if (sscanf(s, "%f,%f,%f", &r, &g, &b) != 3) usage(name); c[0] = 255*r; c[1] = 255*g; c[2] = 255*b; } int main(int argc, char *const *argv) { int force = 0; int x = 0, y = 0; uint8_t *old, *new, *d, *a, *b; char *shadow_old = NULL, *shadow_new = NULL, *out_name = NULL; FILE *out; char *end; int c; while ((c = getopt(argc, argv, "a:b:c:d:fm:n:w:")) != EOF) switch (c) { case 'a': parse_color(a_only, optarg, *argv); break; case 'b': parse_color(b_only, optarg, *argv); break; case 'c': parse_color(both, optarg, *argv); break; case 'd': frame_dist = strtoul(optarg, &end, 0); if (*end) usage(*argv); break; case 'f': force = 1; break; case 'm': parse_color(frame, optarg, *argv); break; case 'n': parse_color(frame_fill, optarg, *argv); break; case 'w': frame_width = strtoul(optarg, &end, 0); if (*end) usage(*argv); break; default: usage(*argv); } switch (argc-optind) { case 2: break; case 3: out_name = argv[optind+2]; break; case 5: out_name = argv[optind+4]; /* fall through */ case 4: shadow_old = argv[optind+2]; shadow_new = argv[optind+3]; break; default: usage(*argv); } old = load_ppm(argv[optind], &x, &y); new = load_ppm(argv[optind+1], &x, &y); d = diff(old, new, x, y); if (shadow_old) { a = load_ppm(shadow_old, &x, &y); b = load_ppm(shadow_new, &x, &y); shadow_diff(a, b, x, y); } if (frame_dist) mark_areas(d, x, y); if (!areas && !force) return 1; if (out_name) { out = fopen(out_name, "w"); if (!out) { perror(out_name); exit(1); } } else { out = stdout; } fprintf(out, "P6\n%d %d\n255\n", x, y); fwrite(d, 1, x*y*3, out); if (fclose(out) == EOF) { perror("fclose"); exit(1); } return 0; }