OpenCV绘制灰度直方图(2)

#include <cv.h>    #include <highgui.h>    #pragma comment( lib, "cv.lib" )    #pragma comment( lib, "cxcore.lib" )    #pragma comment( lib, "highgui.lib" )    int main()   {            IplImage* src=cvLoadImage("lena.jpg",0);            int size=256;            float range[]={0,255};            float* ranges[]={range};            CvHistogram* hist=cvCreateHist(1,&size,CV_HIST_ARRAY,ranges,1);            cvCalcHist(&src,hist,0,NULL);            float max=0;            cvGetMinMaxHistValue(hist,NULL,&max,NULL,NULL);            IplImage* dst=cvCreateImage(cvSize(400,300),8,3);            cvSet(dst,cvScalarAll(255),0);            double bin_width=(double)dst->width/size;            double bin_unith=(double)dst->height/max;            for(int i=0;i<size;i++)            {                      CvPoint p0=cvPoint(i*bin_width,dst->height);                      CvPoint p1=cvPoint((i+1)*bin_width,dst->height-cvGetReal1D(hist->bins,i)*bin_unith);                      cvRectangle(dst,p0,p1,cvScalar(0,255),-1,8,0);            }            cvNamedWindow("src",1);            cvShowImage("src",src);            cvNamedWindow("dst",1);            cvShowImage("dst",dst);            cvWaitKey(0);            cvDestroyAllWindows();            cvReleaseImage(&src);            cvReleaseImage(&dst);            return 0;   }