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/* imagediff - Compare two images
*
* Copyright © 2004 Richard D. Worth
*
* Permission to use, copy, modify, distribute, and sell this software
* and its documentation for any purpose is hereby granted without
* fee, provided that the above copyright notice appear in all copies
* and that both that copyright notice and this permission notice
* appear in supporting documentation, and that the name of Richard Worth
* not be used in advertising or publicity pertaining to distribution
* of the software without specific, written prior permission.
* Richard Worth makes no representations about the suitability of this
* software for any purpose. It is provided "as is" without express
* or implied warranty.
*
* RICHARD WORTH DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
* NO EVENT SHALL RICHARD WORTH BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
* OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Author: Richard D. Worth <richard@theworths.org> */
#include <stdio.h>
#include <stdlib.h>
#include "buffer-diff.h"
#include "xmalloc.h"
int
main (int argc, char *argv[])
{
buffer_diff_result_t result;
cairo_status_t status;
unsigned int ax, ay, bx, by;
if (argc != 3 && argc != 7) {
fprintf (stderr, "Usage: %s image1.png image2.png [ax ay bx by]\n", argv[0]);
fprintf (stderr, "Computes an output image designed to present a \"visual diff\" such that even\n");
fprintf (stderr, "small errors in single pixels are readily apparent in the output.\n");
fprintf (stderr, "The output image is written on stdout.\n");
exit (1);
}
if (argc == 7) {
ax = strtoul (argv[3], NULL, 0);
ay = strtoul (argv[4], NULL, 0);
bx = strtoul (argv[5], NULL, 0);
by = strtoul (argv[6], NULL, 0);
} else {
ax = ay = bx = by = 0;
}
status = png_diff (NULL, argv[1], argv[2], NULL, ax, ay, bx, by, &result);
if (status) {
fprintf (stderr, "Error comparing images: %s\n",
cairo_status_to_string (status));
return 1;
}
if (result.pixels_changed)
fprintf (stderr, "Total pixels changed: %d with a maximum channel difference of %d.\n",
result.pixels_changed,
result.max_diff);
return (result.pixels_changed != 0);
}
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