显示直方图openCV(Displaying histogram plot openCV)

 我有一个我计算过的图像的直方图。 我想将其显示为图像，以便我可以实际看到直方图。 我认为我的问题与缩放有关，虽然我对左上角的0,0开始的坐标系有点困惑。 
 
int rows = channel.rows;
int cols = channel.cols;
int hist[256] = {0};
for(int i = 0; i<rows; i++)
{
    for(int k = 0; k<cols; k++ )
    {
        int value = channel.at<cv::Vec3b>(i,k)[0];
        hist[value] = hist[value] + 1;
    }
}

Mat histPlot = cvCreateMat(256, 500,CV_8UC1);
for(int i = 0; i < 256; i++)
{
    int mag = hist[i];
    line(histPlot,Point(i,0),Point(i,mag),Scalar(255,0,0));
}

namedWindow("Hist",1);
imshow("Hist",histPlot);
 
 这是我创建直方图并显示结果的计算。 如果我在第二次循环中使用mag / 100，那么我会看到一些相似的情节（虽然是颠倒的）。 每当我调整图像的值时，我都会调用此方法，因此直方图也应该改变形状，这似乎不会发生。 任何帮助缩放直方图并正确显示它是值得赞赏的。 

I have the histogram for an image which i have calculated. I want to display this as an image so that I can actually see the histogram. I think my problem is to do with scaling although i am slightly confused over the co ordinate system starting with 0,0 in the top left as well.
 
int rows = channel.rows;
int cols = channel.cols;
int hist[256] = {0};
for(int i = 0; i<rows; i++)
{
    for(int k = 0; k<cols; k++ )
    {
        int value = channel.at<cv::Vec3b>(i,k)[0];
        hist[value] = hist[value] + 1;
    }
}

Mat histPlot = cvCreateMat(256, 500,CV_8UC1);
for(int i = 0; i < 256; i++)
{
    int mag = hist[i];
    line(histPlot,Point(i,0),Point(i,mag),Scalar(255,0,0));
}

namedWindow("Hist",1);
imshow("Hist",histPlot);
 
This is my calculation for creating my histogram and displaying the result. If i do mag/100 in my second loop then i get some resemblance of a plot appearing (although upside down). I call this method whenever i adjust a value of my image, so the histogram should also change shape, which it doesn't appear to do. Any help in scaling the histogram and displaying it properly is appreciated.

原文：https://stackoverflow.com/questions/19916803