/**************************************************************************
*
+ * Copyright 2011 Jose Fonseca
* Copyright 2008-2010 VMware, Inc.
* All Rights Reserved.
*
**************************************************************************/
-#include <stdint.h>
-
-#include <fstream>
+#include <assert.h>
+#include <math.h>
#include "image.hpp"
namespace Image {
-#pragma pack(push,2)
-struct FileHeader {
- uint16_t bfType;
- uint32_t bfSize;
- uint16_t bfReserved1;
- uint16_t bfReserved2;
- uint32_t bfOffBits;
-};
-#pragma pack(pop)
-
-struct InfoHeader {
- uint32_t biSize;
- int32_t biWidth;
- int32_t biHeight;
- uint16_t biPlanes;
- uint16_t biBitCount;
- uint32_t biCompression;
- uint32_t biSizeImage;
- int32_t biXPelsPerMeter;
- int32_t biYPelsPerMeter;
- uint32_t biClrUsed;
- uint32_t biClrImportant;
-};
-
-struct Pixel {
- uint8_t rgbBlue;
- uint8_t rgbGreen;
- uint8_t rgbRed;
- uint8_t rgbAlpha;
-};
-
-
-bool
-Image::writeBMP(const char *filename) const {
- struct FileHeader bmfh;
- struct InfoHeader bmih;
- unsigned x, y;
-
- bmfh.bfType = 0x4d42;
- bmfh.bfSize = 14 + 40 + height*width*4;
- bmfh.bfReserved1 = 0;
- bmfh.bfReserved2 = 0;
- bmfh.bfOffBits = 14 + 40;
-
- bmih.biSize = 40;
- bmih.biWidth = width;
- bmih.biHeight = height;
- bmih.biPlanes = 1;
- bmih.biBitCount = 32;
- bmih.biCompression = 0;
- bmih.biSizeImage = height*width*4;
- bmih.biXPelsPerMeter = 0;
- bmih.biYPelsPerMeter = 0;
- bmih.biClrUsed = 0;
- bmih.biClrImportant = 0;
-
- std::ofstream stream(filename, std::ofstream::binary);
-
- if (!stream)
- return false;
-
- stream.write((const char *)&bmfh, 14);
- stream.write((const char *)&bmih, 40);
-
- unsigned stride = width*4;
-
- if (flipped) {
- for (y = 0; y < height; ++y) {
- const unsigned char *ptr = pixels + y * stride;
- for (x = 0; x < width; ++x) {
- struct Pixel pixel;
- pixel.rgbRed = ptr[x*4 + 0];
- pixel.rgbGreen = ptr[x*4 + 1];
- pixel.rgbBlue = ptr[x*4 + 2];
- pixel.rgbAlpha = ptr[x*4 + 3];
- stream.write((const char *)&pixel, 4);
- }
- }
- } else {
- y = height;
- while (y--) {
- const unsigned char *ptr = pixels + y * stride;
- for (x = 0; x < width; ++x) {
- struct Pixel pixel;
- pixel.rgbRed = ptr[x*4 + 0];
- pixel.rgbGreen = ptr[x*4 + 1];
- pixel.rgbBlue = ptr[x*4 + 2];
- pixel.rgbAlpha = ptr[x*4 + 3];
- stream.write((const char *)&pixel, 4);
+double Image::compare(Image &ref)
+{
+ if (width != ref.width ||
+ height != ref.height ||
+ channels != ref.channels) {
+ return 0.0;
+ }
+
+ const unsigned char *pSrc = start();
+ const unsigned char *pRef = ref.start();
+
+ assert(channels >= 3);
+
+ unsigned long long error = 0;
+ for (unsigned y = 0; y < height; ++y) {
+ for (unsigned x = 0; x < width; ++x) {
+ // FIXME: Ignore alpha channel until we are able to pick a visual
+ // that matches the traces
+ for (unsigned c = 0; c < 3; ++c) {
+ int delta = pSrc[x*channels + c] - pRef[x*channels + c];
+ error += delta*delta;
}
}
+
+ pSrc += stride();
+ pRef += ref.stride();
}
- stream.close();
+ double numerator = error*2 + 1;
+ double denominator = height*width*3ULL*255ULL*255ULL*2;
+ double quotient = numerator/denominator;
+
+ // Precision in bits
+ double precision = -log(quotient)/log(2.0);
- return true;
+ return precision;
}