test/imagediff.c

   1 /* imagediff - Compare two images
   2  *
   3  * Copyright © 2004 Richard D. Worth
   4  *
   5  * Permission to use, copy, modify, distribute, and sell this software
   6  * and its documentation for any purpose is hereby granted without
   7  * fee, provided that the above copyright notice appear in all copies
   8  * and that both that copyright notice and this permission notice
   9  * appear in supporting documentation, and that the name of Richard Worth
  10  * not be used in advertising or publicity pertaining to distribution
  11  * of the software without specific, written prior permission.
  12  * Richard Worth makes no representations about the suitability of this
  13  * software for any purpose.  It is provided "as is" without express
  14  * or implied warranty.
  15  *
  16  * RICHARD WORTH DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  17  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
  18  * NO EVENT SHALL RICHARD WORTH BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  19  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
  20  * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
  21  * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  22  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  23  *
  24  * Author: Richard D. Worth <richard@theworths.org> */
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28
  29 #include "buffer-diff.h"
  30 #include "xmalloc.h"
  31
  32 int
  33 main (int argc, char *argv[])
  34 {
  35     buffer_diff_result_t result;
  36     cairo_status_t status;
  37
  38     unsigned int ax, ay, bx, by;
  39
  40     if (argc != 3 && argc != 7) {
  41         fprintf (stderr, "Usage: %s image1.png image2.png [ax ay bx by]\n", argv[0]);
  42         fprintf (stderr, "Computes an output image designed to present a \"visual diff\" such that even\n");
  43         fprintf (stderr, "small errors in single pixels are readily apparent in the output.\n");
  44         fprintf (stderr, "The output image is written on stdout.\n");
  45         exit (1);
  46     }
  47
  48     if (argc == 7) {
  49         ax = strtoul (argv[3], NULL, 0);
  50         ay = strtoul (argv[4], NULL, 0);
  51         bx = strtoul (argv[5], NULL, 0);
  52         by = strtoul (argv[6], NULL, 0);
  53     } else {
  54         ax = ay = bx = by = 0;
  55     }
  56
  57     status = image_diff (argv[1], argv[2], NULL, ax, ay, bx, by, &result);
  58
  59     if (status) {
  60         fprintf (stderr, "Error comparing images: %s\n",
  61                  cairo_status_to_string (status));
  62         return 1;
  63     }
  64
  65     if (result.pixels_changed)
  66         fprintf (stderr, "Total pixels changed: %d with a maximum channel difference of %d.\n",
  67                  result.pixels_changed,
  68                  result.max_diff);
  69
  70     return (result.pixels_changed != 0);
  71 }