imgproc模塊--直方圖比較

1.目的
（1）如何使用OpenCV函數 compareHist 產生一個表達兩個直方圖的相似度的數值。
（2）如何使用不同的對比標準來對直方圖進行比較。

2.原理
[1]直方圖衡量標準
a.Correlation ( CV_COMP_CORREL )

b.Chi-Square（CV_COMP_CHISQR）

c.Intersection(CV_COMP_INTERSECT)

d.Bhattacharyya距離（CV_COMP_BHATTACHARYYA）

3.部分代碼解釋

        /*
        compareHist參數解釋
        test_hist:輸入直方圖1
        test1_hist:輸入直方圖2
        compareMethod:比較方法
        */
        double test_test1 = compareHist(test_hist, test1_hist, compareMethod);
        double test_test2 = compareHist(test_hist, test2_hist, compareMethod);
        double test1_test2 = compareHist(test1_hist, test2_hist, compareMethod);

4.完整代碼
（1）CommonInclude.h

#ifndef COMMON_INCLUDE
#define COMMON_INCLUDE
#include<iostream>
#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/imgproc/imgproc.hpp>
using namespace std;
using namespace cv;
#endif

（2）CompareHist.cpp

#include"CommonInclude.h"

int main(int argc, char** argv){
    if(argc<4){
        cout << "more parameters are required!!!" << endl;
        return(-1);
    }
    Mat test;
    Mat test1;
    Mat test2;
    test = imread(argv[1]);
    test1 = imread(argv[2]);
    test2 = imread(argv[3]);
    if(!test.data || !test1.data || !test2.data){
        cout << "error to read images!!!" << endl;
        return(-1);
    }
    cvtColor(test, test, CV_BGR2HSV);
    cvtColor(test1, test1, CV_BGR2HSV);
    cvtColor(test2, test2, CV_BGR2HSV);

    MatND test_hist;
    MatND test1_hist;
    MatND test2_hist;
    int channels[] = {0,1};
    int h_bins = 50;
    int s_bins = 32;
    int histSize[] = {h_bins, s_bins};
    float h_range[] = {0,256};
    float s_range[] = {0,180};
    const float* histRange[] = {h_range, s_range};

    calcHist(&test, 1, channels, Mat(), test_hist, 2, histSize, histRange, true, false);
    normalize(test_hist, test_hist, 0, 1, NORM_MINMAX, -1, Mat());
    calcHist(&test1, 1, channels, Mat(), test1_hist, 2, histSize, histRange, true, false);
    normalize(test1_hist, test1_hist, 0, 1, NORM_MINMAX, -1, Mat());
    calcHist(&test2, 1, channels, Mat(), test2_hist, 2, histSize, histRange, true, false);
    normalize(test2_hist, test2_hist, 0, 1, NORM_MINMAX, -1, Mat());
    for(int i=0; i<4; i++){
        int compareMethod = i;
        /*
        compareHist參數解釋
        test_hist:輸入直方圖1
        test1_hist:輸入直方圖2
        compareMethod:比較方法
        */
        double test_test1 = compareHist(test_hist, test1_hist, compareMethod);
        double test_test2 = compareHist(test_hist, test2_hist, compareMethod);
        double test1_test2 = compareHist(test1_hist, test2_hist, compareMethod);
        cout << "method " << i  << ":" << test_test1 << " " << test_test2 << " " << test1_test2 << endl;
    }
    return(0);
}

參考文獻
1.http://www.opencv.org.cn/opencvdoc/2.3.2/html/doc/tutorials/imgproc/histograms/histogram_comparison/histogram_comparison.html