计算N维数据的平均值meanStdDev(均值及标准差)
方差
协方差calcCovarMatrix
#include <opencv2/opencv.hpp>
#include <iostream>
#include <opencv2/face.hpp>
using namespace std;
using namespace cv;
int main(int argc, char** argv)
{
Mat src;
src = imread("../path.jpg");
if (src.empty())
{
cout << "could not load image..." <<