OpenCV直方图计算

#include <opencv2/opencv.hpp>
#include <vector>using namespace cv;
using namespace std;int main()
{cout << "直方图calcHist" << endl;Mat src = imread("left.png", IMREAD_GRAYSCALE);if (src.empty()){cout << "read image failed." << endl;return -1;}imshow("gray_img", src);Mat hist;int histSize = 256;calcHist(&src, 1, 0, Mat(), hist, 1, &histSize, 0);double maxVal = 0;double minVal = 0;minMaxLoc(hist, &minVal, &maxVal, 0, 0);int zoom = 2;Mat histImg(histSize * zoom, histSize * zoom, CV_8U, Scalar(255));int hpt = static_cast<int>(0.9 * histSize);for (int h = 0; h < histSize; h++){float binVal = hist.at<float>(h);if (binVal > 0){int intensity = static_cast<int>(binVal * hpt / maxVal);line(histImg, Point(h * zoom, histSize * zoom), Point(h * zoom, (histSize - intensity) * zoom), Scalar(0), zoom);}}imshow("hist_img", histImg);cout << "直方图均衡化equalizeHist" << endl;Mat result;equalizeHist(src, result);imshow("equalizeHist", result);cout << "直方图反向投影calcBackProject" << endl;Mat imageROI = src(Rect(400,20,150,80));Mat hist2;calcHist(&imageROI, 1, 0, Mat(), hist2, 1, &histSize, 0);normalize(hist2, hist2, 1.0);Mat backP;calcBackProject(&src, 1, 0, hist2, backP, 0, 255.0);Mat mask;threshold(backP, mask, 30, 255, THRESH_BINARY);imshow("backProject", mask);cout << "积分图像" << endl;Mat integralImg;integral(src, integralImg, CV_32S);waitKey();return 0;
}