opencv学习笔记——minMaxIdx函数的含义及用法

opencv中有时需要对Mat数据需要对其中的数据求取最大值和最小值。opencv提供了直接的函数

CV_EXPORTS_W void minMaxLoc(InputArray src, CV_OUT double* minVal,
                           CV_OUT double* maxVal=, CV_OUT Point* minLoc=,
                           CV_OUT Point* maxLoc=, InputArray mask=noArray());
CV_EXPORTS void minMaxIdx(InputArray src, double* minVal, double* maxVal,
                          int* minIdx=, int* maxIdx=, InputArray mask=noArray());  

实现代码如下所示：

    #include <iostream>
    #include <cstdlib>
    #include <cmath>
    #include <iomanip>
    #include <algorithm>  

    #include "opencv2/core/core.hpp"
    #include "opencv2/highgui/highgui.hpp"
    #include "opencv2/imgproc/imgproc.hpp"
    #include "opencv2/contrib/contrib.hpp"  

    using namespace std;
    using namespace cv;  

    int main(int argc, char* argv[])
    {
    #pragma region min_max  

        float Tval = 0.0;
        float RawData[][] = {{4.0,1.0,3.0},{8.0,7.0,9.0}};
        Mat RawDataMat(,,CV_32FC1,RawData);  

        for (int j = ; j < ; j++)
        {
            for (int i = ; i < ; i++)
            {
                //Tval = RawData[j][i];             //No problem !!!
                Tval = RawDataMat.at<float>(j,i);
                cout << "(j,i) = "<<j<<","<<i<<"\t"<<Tval<<endl;
            }
        }  

        double minv = 0.0, maxv = 0.0;
        double* minp = &minv;
        double* maxp = &maxv;  

        minMaxIdx(RawDataMat,minp,maxp);  

        cout << "Mat minv = " << minv << endl;
        cout << "Mat maxv = " << maxv << endl;  

    #pragma endregion  

        return ;
    }