opencv:直方图操作

示例程序：

#include <opencv.hpp>using namespace cv;using namespace std;int main(){    Mat src, dst;    //load img;    src = imread("001.jpg",1);    if (!src.data)    {        printf("error");        return -1;            }    imshow("1", src);    //分成三个通道    vector<Mat> rgb_planes; // 保存在stl容器里    split(src, rgb_planes);    // 设置直方图尺寸     int histSize = 255;        Mat histImage(400, 400, CV_8UC1, Scalar(0));    int bin_w = cvRound((double)400 / histSize);    //设置范围    float range[] = { 0, 255 };    const float * histRange = { range };    bool uniform = true; bool accumulate = false;    Mat r_hist, g_hist, b_hist; // 用于保存三个通道的直方图    //计算直方图    calcHist(&rgb_planes[1], 1,0,Mat(),r_hist,1, &histSize, &histRange, uniform, accumulate);    normalize(r_hist, r_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat());  // 直方图归一化    for (int i = 1; i < histSize; i++)    {        line(histImage, Point(bin_w * (i - 1), 400 - cvRound(r_hist.at<float>(i - 1))), Point(bin_w * (i), 400 - cvRound(r_hist.at<float>(i))), Scalar(255), 1, 8, 0);    }    imshow("dst", histImage);    waitKey(0);        return 0;}