1 /**************************************************************************
3 * Copyright 2011 Jose Fonseca
4 * Copyright 2008-2010 VMware, Inc.
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 **************************************************************************/
37 double Image::compare(Image &ref)
39 if (width != ref.width ||
40 height != ref.height ||
41 channels != ref.channels) {
45 const unsigned char *pSrc = start();
46 const unsigned char *pRef = ref.start();
48 assert(channels >= 3);
50 unsigned long long error = 0;
51 for (unsigned y = 0; y < height; ++y) {
52 for (unsigned x = 0; x < width; ++x) {
53 // FIXME: Ignore alpha channel until we are able to pick a visual
54 // that matches the traces
55 for (unsigned c = 0; c < 3; ++c) {
56 int delta = pSrc[x*channels + c] - pRef[x*channels + c];
65 double numerator = error*2 + 1;
66 double denominator = height*width*3ULL*255ULL*255ULL*2;
67 double quotient = numerator/denominator;
70 double precision = -log(quotient)/log(2.0);
76 } /* namespace Image */