此方法使用直方图模型比对两张图片，如果两张图片一模一样的话，结果为0.00；比对的结果越小，图片相似性越高;
适用于比较两张尺寸大小一致的图片，对于大小不一致的图片，只能比较其相似性；
-(double)CompareHist:(IplImage*)image1 withParam2:(IplImage*)image2
{
int hist_size = 256;
float range[] = {0,255};
IplImage *gray_plane = cvCreateImage(cvGetSize(image1), 8, 1);
cvCvtColor(image1, gray_plane, CV_BGR2GRAY);
CvHistogram *gray_hist = cvCreateHist(1, &hist_size, CV_HIST_ARRAY);
cvCalcHist(&gray_plane, gray_hist);
IplImage *gray_plane2 = cvCreateImage(cvGetSize(image2), 8, 1);
cvCvtColor(image2, gray_plane2, CV_BGR2GRAY);
CvHistogram *gray_hist2 = cvCreateHist(1, &hist_size, CV_HIST_ARRAY);
cvCalcHist(&gray_plane2, gray_hist2);
return cvCompareHist(gray_hist, gray_hist2, CV_COMP_BHATTACHARYYA);
}
ios--OpenCV--cvCompareHist使用直方图模型(CvHistogram)比对两张图片,布布扣,bubuko.com