OpenCV：绘制图像的BGR三通道直方图

最新推荐文章于 2024-09-22 22:27:06 发布

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最新推荐文章于 2024-09-22 22:27:06 发布 · 2.2k 阅读

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#OpenCV

本文介绍了如何利用OpenCV库在Python中分别绘制BGR三通道的图像直方图。通过这一过程，读者可以理解每个通道颜色在图像中的分布情况。

<span style="font-size:14px;">#include <opencv\cv.h>
#include <opencv\highgui.h>
#include <opencv\cxcore.h>

IplImage* DrawHistogram(CvHistogram* hist, float scaleX = 1, float scaleY = 1){

    float histMax = 0;
    cvGetMinMaxHistValue(hist, 0, &histMax, 0, 0); //获取直方图的最大值

    IplImage* imageHist = cvCreateImage(cvSize(256*scaleX, 64*scaleY), 8, 1);
    cvZero(imageHist);

    for(int i = 0; i < 255; ++i){

        //查询直方图每个单位的x值对应的y值
        float histValue = cvQueryHistValue_1D(hist, i);
        float nextValue = cvQueryHistValue_1D(hist, i+1);

        CvPoint pt1 = cvPoint(i* scaleX, 64*scaleY);
        CvPoint pt2 = cvPoint((i+1)*scaleX, 64*scaleY);
        CvPoint pt3 = cvPoint((i+1)*scaleX, 64*scaleY - (nextValue/histMax)*64*scaleY);
        CvPoint pt4 = cvPoint(i*scaleX, 64*scaleY - (histValue/histMax)*64*scaleY);

        int numPts = 5;
        CvPoint pts[5];
        pts[0] = pt1;
        pts[1] = pt2;