opencv —— compareHist 直方图比较

对比直方图：compareHist 函数

double compareHist(InputArray H1, InputArray H2, int method);

  • H1，H2，是要进行比较的直方图。
  • method，比较方法。有如下选择：
方法名 标识符 计算公式

相关 

Correlation

 
HISTCMP_CORREL
 d(H_1,H_2) = \frac{\sum_I (H_1(I) - \bar{H_1}) (H_2(I) - \bar{H_2})}{\sqrt{\sum_I(H_1(I) - \bar{H_1})^2 \sum_I(H_2(I) - \bar{H_2})^2}}

其中 \bar{H_k} = \frac{1}{N} \sum _J H_k(J)

N 是直方图中bin的数目。

卡方

Chi-square

 
HISTCMP_CHISQR
 d(H_1,H_2) = \sum _I \frac{\left(H_1(I)-H_2(I)\right)^2}{H_1(I)+H_2(I)}

相交 

Intersection

HISTCMP_INTERSECT

 d(H_1,H_2) = \sum _I \min (H_1(I), H_2(I))

巴氏距离 

Bhattacharyya

 
HISTCMP_BHATTACHARYYA
 d(H_1,H_2) = \sqrt{1 - \frac{1}{\sqrt{\bar{H_1} \bar{H_2} N^2}} \sum_I \sqrt{H_1(I) \cdot H_2(I)}}

 

代码示例：

#include<opencv.hpp>
#include<iostream>
#include<string>
using namespace std;
using namespace cv;
int main() {
    Mat src1 = imread("C:/Users/齐明洋/Desktop/证件照/6.jpg");
    Mat src2 = imread("C:/Users/齐明洋/Desktop/证件照/8.jpg");
    Mat src3 = imread("C:/Users/齐明洋/Desktop/证件照/10.jpg");
    imshow("src1", src1);
    imshow("src2", src2);
    imshow("src3", src3);

    //将图片转换成 HSV 类型
    //对 HS 两通道进行直方图统计
    cvtColor(src1, src1, COLOR_BGR2HSV);
    cvtColor(src2, src2, COLOR_BGR2HSV);
    cvtColor(src3, src3, COLOR_BGR2HSV);

    int channels[] = { 0,1 };
    int histsize[] = { 180,255 };
    float r1[] = { 0,180 };
    float r2[] = { 0,255 };
    const float *ranges[] = { r1,r2 };
    Mat hist1, hist2, hist3;
    calcHist(&src1, 3, channels, Mat(), hist1, 2, histsize, ranges, true);
    //https://www.cnblogs.com/bjxqmy/p/12292421.html
    normalize(hist1, hist1, 1, 0, NORM_L1);

    calcHist(&src2, 3, channels, Mat(), hist2, 2, histsize, ranges, true);
    normalize(hist2, hist2, 1, 0, NORM_L1);

    calcHist(&src3, 3, channels, Mat(), hist3, 2, histsize, ranges, true);
    normalize(hist3, hist3, 1, 0, NORM_L1);
    
    int method[] = { HISTCMP_CORREL,HISTCMP_CHISQR,HISTCMP_INTERSECT,HISTCMP_BHATTACHARYYA };
    string names[] = { "HISTCMP_CORREL","HISTCMP_CHISQR","HISTCMP_INTERSECT","HISTCMP_BHATTACHARYYA" };
    for (int i = 0; i < 4; i++) {
        cout << names[i] << ":" << endl;
        cout << "src1 and src1 :" << compareHist(hist1, hist1, method[i]) << endl;
        cout << "src1 and src2 :" << compareHist(hist1, hist2, method[i]) << endl;
        cout << "src1 and src3 :" << compareHist(hist1, hist3, method[i]) << endl;
        cout << endl;
    }
    waitKey(0);
}

效果演示：

 

 

借鉴博客：https://blog.csdn.net/qq_18343569/article/details/48028457

 

posted @ 2020-02-28 20:28  狂奔的小学生  阅读(3323)  评论(0)  编辑  收藏  举报