opencv直方图显示

Mat calcHistImage(Mat Image){    const int channels[1] = { 0 };    const int histSize[1] = { 256 };    float hranges[2] = { 0, 255 };    const float* ranges[1] = { hranges };    Mat hist;    calcHist(&Image, 1, channels, Mat(), hist, 1, histSize, ranges);    double maxVal = 0;    double minVal = 0;    //找到直方图中的最大值和最小值    minMaxLoc(hist, &minVal, &maxVal, 0, 0);    int histHeight = hist.rows;    Mat histImg(histHeight, 256, CV_8U, Scalar(255));    // 设置最大峰值为图像高度的90%    int hpt = static_cast<int>(0.9*histHeight);    for (int h = 0; h < histHeight; h++)    {        int intensity = static_cast<int>(hist.at<float>(h)*hpt / maxVal);        line(histImg, Point(h, histHeight), Point(h, histHeight - intensity), Scalar::all(0));    }    return histImg;}