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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 "read_png.h"
#include "write_png.h"
#include "xmalloc.h"
int
main (int argc, char *argv[])
{
unsigned char *buffer_a;
unsigned int width_a, height_a, stride_a;
unsigned char *buffer_b;
unsigned int width_b, height_b, stride_b;
unsigned char *buffer;
unsigned int width, height, stride;
int buffer_size, total_pixels_changed;
if (argc < 2) {
fprintf (stderr, "Usage: %s image1.png image2.png\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);
}
read_png_argb32 (argv[1], &buffer_a, &width_a, &height_a, &stride_a);
read_png_argb32 (argv[2], &buffer_b, &width_b, &height_b, &stride_b);
if ((width_a == width_b) && (height_a == height_b) && (stride_a == stride_b))
{
width = width_a;
height = height_a;
stride = stride_a;
} else {
fprintf (stderr, "Error. Both images must be the same size\n");
return 1;
}
buffer_size = stride * height;
buffer = xmalloc (buffer_size);
total_pixels_changed = buffer_diff (buffer_a, buffer_b, buffer,
width_a, height_a, stride_a);
if (total_pixels_changed)
fprintf (stderr, "Total pixels changed: %d\n", total_pixels_changed);
write_png_argb32 (buffer, stdout, width, height, stride);
free (buffer);
return 0;
}
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