1 /*
2 * Copyright (c) 2011, Tom Distler (http://tdistler.com)
3 * All rights reserved.
4 *
5 * The BSD License
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 *
10 * - Redistributions of source code must retain the above copyright notice,
11 * this list of conditions and the following disclaimer.
12 *
13 * - Redistributions in binary form must reproduce the above copyright notice,
14 * this list of conditions and the following disclaimer in the documentation
15 * and/or other materials provided with the distribution.
16 *
17 * - Neither the name of the tdistler.com nor the names of its contributors may
18 * be used to endorse or promote products derived from this software without
19 * specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include "decimate.h"
35 #include <stdlib.h>
36
_iqa_decimate(float * img,int w,int h,int factor,const struct _kernel * k,float * result,int * rw,int * rh)37 int _iqa_decimate(float *img, int w, int h, int factor, const struct _kernel *k, float *result, int *rw, int *rh)
38 {
39 int x,y;
40 int sw = w/factor + (w&1);
41 int sh = h/factor + (h&1);
42 int dst_offset;
43 float *dst=img;
44
45 if (result)
46 dst = result;
47
48 /* Downsample */
49 for (y=0; y<sh; ++y) {
50 dst_offset = y*sw;
51 for (x=0; x<sw; ++x,++dst_offset) {
52 dst[dst_offset] = _iqa_filter_pixel(img, w, h, x*factor, y*factor, k, 1.0f);
53 }
54 }
55
56 if (rw) *rw = sw;
57 if (rh) *rh = sh;
58 return 0;
59 }
60