计算图像/数据的直方图

可通过opencv中的计算直方图函数clacHist计算出直方图，对于非图像数据可以通过存入Mat类型中使用该方法计算

#include<iostream>
#include<opencv2\opencv.hpp>
#include<time.h>

using namespace cv;

int main()
{
    Mat src(Size(1000, 1), CV_8UC1);
    srand(time(NULL));
    for (int i = 0; i < 1000; ++i)
    {
        src.at<uchar>(0, i) = rand() % 100+50;
    }
    Mat imageHist;
    Mat imageNormalize;
    const int histSize = 255;   //定义灰度级数量
    float histR[] = { 0,255 };   //定义每个维度下取值范围
    const float *histRange = histR;

    //计算直方图
    calcHist(&src, 1, 0, Mat(), imageHist, 1, &histSize, &histRange, true, false);

    //直方图归一化到范围[0,histSize]
    normalize(imageHist, imageNormalize, 0, histSize, NORM_MINMAX, -1, Mat());

    //创建直方图画布
    Mat imageShowHist(histSize, histR[1], CV_8UC3, Scalar(255, 0, 0));

    //分别画出每个灰度级下的直方图分布
    for (int i = 0; i<histSize; i++)
    {
        line(imageShowHist, Point(i, histR[1]), Point(i, histR[1] - cvRound(imageNormalize.at<float>(i))), Scalar(0, 255, 255), 1, 8, 0);
    }
    imshow("Hist", imageShowHist);
    waitKey();
    return 0;
}