cvCompareHist() 直方图匹配

比较两个直方图的相似程度

函数原型和使用方法都很简单

/* Compares two histogram */
CVAPI(double)  cvCompareHist( const CvHistogram* hist1,
                              const CvHistogram* hist2,
                              int method);

method是指4种不同的匹配方法

测试用图（两组，一组是找茬图，一组是镜像图）：

    

       

程序代码：

#include 
#include 
#include 
using namespace std;

int main()
{
	IplImage *img1 = cvLoadImage("test3.jpg");
	IplImage *img2 = cvLoadImage("test4.jpg");
	IplImage *img_gray1 = cvCreateImage(cvGetSize(img1),IPL_DEPTH_8U,1);
	IplImage *img_gray2 = cvCreateImage(cvGetSize(img2),IPL_DEPTH_8U,1);

	cvNamedWindow("img1",CV_WINDOW_AUTOSIZE);
	cvShowImage("img1",img1);
	cvNamedWindow("img2",CV_WINDOW_AUTOSIZE);
	cvShowImage("img2",img2);

	cvCvtColor(img1,img_gray1,CV_BGR2GRAY);
	cvNamedWindow("img_gray1",CV_WINDOW_AUTOSIZE);
	cvShowImage("img_gray1",img_gray1);
	cvCvtColor(img2,img_gray2,CV_BGR2GRAY);
	cvNamedWindow("img_gray2",CV_WINDOW_AUTOSIZE);
	cvShowImage("img_gray2",img_gray2);

	int hist_size=256;//直方图的横轴长度  
	int hist_height=256;//直方图的纵轴高度 
	float range[]={0,255}; //灰度级的范围
	float* ranges[]={range};

	CvHistogram *Histogram1 = cvCreateHist(1,&hist_size,CV_HIST_ARRAY,ranges,1);
	CvHistogram *Histogram2 = cvCreateHist(1,&hist_size,CV_HIST_ARRAY,ranges,1);

	cvCalcHist(&img_gray1,Histogram1,0,0);//计算直方图
	cvNormalizeHist(Histogram1,1.0);//归一化直方图
	cvCalcHist(&img_gray2,Histogram2,0,0);//计算直方图
	cvNormalizeHist(Histogram2,1.0);//归一化直方图

	printf("CV_COMP_CORREL : %.4f\n",cvCompareHist(Histogram1,Histogram2,CV_COMP_CORREL));
	printf("CV_COMP_CHISQR : %.4f\n",cvCompareHist(Histogram1,Histogram2,CV_COMP_CHISQR));
	printf("CV_COMP_INTERSECT : %.4f\n",cvCompareHist(Histogram1,Histogram2,CV_COMP_INTERSECT));
	printf("CV_COMP_BHATTACHARYYA : %.4f\n",cvCompareHist(Histogram1,Histogram2,CV_COMP_BHATTACHARYYA));

	cvWaitKey(0);
	cvDestroyAllWindows();
	cvReleaseImage(&img1);
	cvReleaseImage(&img2);

	return 0;
}

运行结果：