opencv 绘制H-S直方图

#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/imgproc/imgproc.hpp>


using namespace cv;
using namespace std;


int main ()
{
Mat srcimg=imread("test.jpg");
Mat Hsvimg;
cvtColor(srcimg,Hsvimg,COLOR_BGR2HSV);


int huebinnum=30;//色调量化
int saturationbinnum=32;  //饱和度量化


int histsize[]={huebinnum,saturationbinnum};


float hueRange[]={0,180};//色调的变化范围
float saturationRange[]={0,256};//饱和度的变化范围


const float *ranges[]={hueRange,saturationRange};


MatND dstHist;   //MatND 储存直方图的一种数据结构


int channels[]={0,1};//计算第0，1通道的直方图


calcHist(&Hsvimg,1,channels,Mat(),dstHist,2,histsize,ranges,true,false);
//进行直方图计算


//为绘制直方图准备参数
double maxVaule=0;
minMaxLoc(dstHist,0,&maxVaule,0,0);//查找dstHist全局最大最小值后存入maxVaule


int scale=10;


Mat histImg=Mat::zeros(saturationbinnum*scale,huebinnum*10,CV_8UC3);


for(int hue=0;hue<huebinnum;hue++)
for(int saturation=0;saturation<saturationbinnum;saturation++)
{
float binValue = dstHist.at<float>(hue,saturation);//直方图直条的值


int intensity=cvRound(binValue*255/maxVaule);  //强度
rectangle(histImg,Point(hue*scale,saturation*scale),Point((hue+1)*scale-1,(saturation+1)*scale-1),Scalar::all(intensity),CV_FILLED);




}
cvtColor(histImg,histImg,COLOR_HSV2BGR);
imshow("hist",histImg);
waitKey(0);
return 0;

}