對比直方圖：compareHist 函數
double compareHist(InputArray H1, InputArray H2, int method);
- H1，H2，是要進行比較的直方圖。
- method，比較方法。有如下選擇：
| 方法名 | 標識符 | 計算公式 |
| 相關 Correlation |
HISTCMP_CORREL |
 其中
|
| 卡方 Chi-square |
HISTCMP_CHISQR |
 |
| 相交 Intersection |
HISTCMP_INTERSECT |
 |
| 巴氏距離 Bhattacharyya |
HISTCMP_BHATTACHARYYA |
 |
是直方圖中bin的數目。
代碼示例：
#include<opencv.hpp> #include<iostream> #include<string>
using namespace std; using namespace cv; int main() { Mat src1 = imread("C:/Users/齊明洋/Desktop/證件照/6.jpg"); Mat src2 = imread("C:/Users/齊明洋/Desktop/證件照/8.jpg"); Mat src3 = imread("C:/Users/齊明洋/Desktop/證件照/10.jpg"); imshow("src1", src1); imshow("src2", src2); imshow("src3", src3); //將圖片轉換成 HSV 類型 //對 HS 兩通道進行直方圖統計
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：
借鑒博客：https://blog.csdn.net/qq_18343569/article/details/48028457