Google图像对比基本算法的简单实现
#include <cv.h> #include <highgui.h> #include <stdlib.h> //计算图像感知hash值。详情看:http://blog.csdn.net/lhfslhfs/article/details/9157845 int64 CalcImagePerceptualHashKey(const IplImage* pImage) { IplImage* pTheImage8X8 = cvCreateImage(cvSize(8, 8), pImage->depth, pImage->nChannels); IplImage* pGrayscaleImage = cvCreateImage(cvSize(8, 8), 8, 1); cvResize(pImage, pTheImage8X8, CV_INTER_AREA); cvConvertImage(pTheImage8X8, pGrayscaleImage); cvReleaseImage(&pTheImage8X8); //计算平均值 float fElementMean = 0; for (int y = 0; y < 8; ++y) { for (int x = 0; x < 8; ++x) { unsigned char& cElem = *(unsigned char*)(pGrayscaleImage->imageData + x + y * pGrayscaleImage->widthStep); cElem = (unsigned char)(cElem / (float)255 * 64); fElementMean += cElem; } } fElementMean /= 64; unsigned char cElementKey = 0; int64 key = 0; unsigned char* pKeyPtr = (unsigned char*) for (int y = 0; y < 8; ++y) { for (int x = 0; x < 8; ++x) { if (fElementMean > *(unsigned char*)(pGrayscaleImage->imageData + x + y * pGrayscaleImage->widthStep)) { //小于平均值即为0。 cElementKey <<= 1; } else { //否则即为1 cElementKey <<= 1; cElementKey |= 1; } } pKeyPtr[y] = cElementKey; } cvReleaseImage(&pGrayscaleImage); return key; } //比较2个key的相似度,结果以1为最相似,0为不相似。 float CompareImageKeySimilarity(int64 key1, int64 key2) { int64 keyResult = key1 ^ key2; int nOneCount = 0; int i = 64; while(i--) { if ((keyResult & 1) == 1) nOneCount++; keyResult >>= 1; } printf("nOneCount = %dn", nOneCount); return nOneCount == 0 ? 1 : (64 - nOneCount) / (float)64; } int main(int argc, char* argv[]) { IplImage* pSrc1 = cvLoadImage("D:\cvImg\gujinlin1.jpg"); IplImage* pSrc2 = cvLoadImage("D:\cvImg\gujinlin2.jpg"); int64 key1 = CalcImagePerceptualHashKey(pSrc1); int64 key2 = CalcImagePerceptualHashKey(pSrc2); printf("key1 = 0x%llX, key2 = 0x%llX, Similarity = %.2fn", key1, key2, CompareImageKeySimilarity(key1, key2)); return 0; }