opencv——灰度直方图

#include <opencv2/opencv.hpp>#include <stdio.h>// HIstogram.cpp : 定义控制台应用程序的入口点。  //    #define cvQueryHistValue_1D( hist, idx0 )   ((float)cvGetReal1D( (hist)->bins, (idx0)))   int main()  {      IplImage* src= cvLoadImage("C:\\Users\\wxh\\Documents\\Visual Studio 2010\\Projects\\9.24\\9.24\\1.jpg");      IplImage* gray_dst= cvCreateImage(cvGetSize(src), 8, 1);      cvCvtColor(src, gray_dst, CV_BGR2GRAY);        //一维维数      int dims= 1;      //直方图的尺寸      int size= 256;      //直方图的高度      int height = 256;      //灰度图的范围0到255      float range[]= {0, 256};      float *ranges[]= {range};             //创建一维直方图      CvHistogram* hist;      hist= cvCreateHist(dims, &size, CV_HIST_ARRAY, ranges, 1);              //计算灰度图的一维直方图      cvCalcHist(&gray_dst, hist, 0, 0);      //归一化直方图      cvNormalizeHist(hist, 1.0);        int scale= 2;      //创建图像，用于显示直方图      IplImage* hist_img= cvCreateImage(cvSize(size* scale, height), 8, 3);      //图像置零       cvZero(hist_img);         //计算直方图的最大方块值,初始化为0       float max_value= 0;       cvGetMinMaxHistValue(hist, 0, &max_value, 0, 0);         //绘制直方图       for(int i=0; i<size; i++)       {           float bin_val= cvQueryHistValue_1D(hist,i);   //像素i的概率           int intensity = cvRound(bin_val* height/ max_value);  // 绘制的高度           cvRectangle(hist_img,                              cvPoint(i* scale, height- 1),                              cvPoint((i+1)* scale- 1, height- intensity),                              CV_RGB(255, 255, 255));       }         cvNamedWindow("gray");       cvShowImage("gray", gray_dst);       cvNamedWindow("Histogram");       cvShowImage("Histogram", hist_img);         cvWaitKey(0);         cvReleaseImage(&src);       cvReleaseImage(&gray_dst);       cvReleaseImage(&hist_img);         cvDestroyWindow("gray");       cvDestroyWindow("Histogram");         return 0;  }