结果compareHist在openCV [英] results compareHist in openCV

问题描述

我试图比较两个我存储为数组的直方图。我是新的与c + +接口（cv :: Mat）和计算直方图在OpenCV。

I'm trying to compare two histograms which I stored as an array. I'm new with the c++ interface (cv::Mat) and calculating histograms in OpenCV.

我的代码：

int testArr1[4] = {12, 10, 11, 11};
int testArr2[4] = {12, 0, 11, 0};
cv::Mat M1 = cv::Mat(1,4,CV_8UC1, testArr1);
cv::Mat M2 = cv::Mat(1,4,CV_8UC1, testArr2);

int histSize = 4;
float range[] = {0, 20};
const float* histRange = {range};
bool uniform = true;
bool accumulate = false;
cv::Mat a1_hist, a2_hist;

cv::calcHist(&M1, 1, 0, cv::Mat(), a1_hist, 1, &histSize, &histRange, uniform, accumulate );
cv::calcHist(&M2, 1, 0, cv::Mat(), a2_hist, 1, &histSize, &histRange, uniform, accumulate );

double compar_c = cv::compareHist(a1_hist, a2_hist, CV_COMP_CORREL);
double compar_chi = cv::compareHist(a1_hist, a2_hist, CV_COMP_CHISQR);
double compar_bh = cv::compareHist(a1_hist, a2_hist, CV_COMP_BHATTACHARYYA);
double compar_i = cv::compareHist(a1_hist, a2_hist, CV_COMP_INTERSECT);
cout << "compare(CV_COMP_CORREL): " << compar_c << "\n";
cout << "compare(CV_COMP_CHISQR): " << compar_chi << "\n";
cout << "compare(CV_COMP_BHATTACHARYYA): " << compar_bh << "\n";
cout << "compare(CV_COMP_INTERSECT): " << compar_i << "\n";

结果有点意外：

compare(CV_COMP_CORREL): 1
compare(CV_COMP_CHISQR): 0
compare(CV_COMP_BHATTACHARYYA): 0
compare(CV_COMP_INTERSECT): 4

对于交集，例如，我预计像0.5。我做错了什么？我可以不把数组在cv :: mat？或者我选择了错误的直方图设置？

For intersection, for example, I expected something like 0.5. What am I doing wrong? Can I not put arrays in a cv::mat? Or did I choose the wrong histogram "settings"?

推荐答案

问题是你的前4行，的整数到字符矩阵。构造函数假定为一个char数组，因此无法正确读取值。您的矩阵M1和M2不包含正确的值。

The problem are your first 4 lines where you are converting the c array of integers to a matrix of chars. The constructor assumes a char array and therefore can't read the values properly. Your matrices M1 and M2 don't contain the correct values.

但是如果您更改以下行，以便数组的类型匹配矩阵的类型：

But if you change the following lines, so that the type of the array matches the type of the matrix:

char testArr1[4] = {12, 10, 11, 11};
char testArr2[4] = {12, 0, 11, 0};

我从程序中获得以下输出：

I get the following output from your program:

compare(CV_COMP_CORREL): 0.57735
compare(CV_COMP_CHISQR): 2.66667
compare(CV_COMP_BHATTACHARYYA): 0.541196
compare(CV_COMP_INTERSECT): 2

这篇关于结果compareHist在openCV的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！