OpenCV Images
转自:https://blog.youkuaiyun.com/sc944201630/article/details/82222909
行列与坐标系对应关系
行rows:Y (Height)
列cols:X (Width)
在Mat类型变量访问时下标是反着写的,即按照(y, x)的关系形式访问,下面通过代码展示来说明这一点。
#include "opencv2/core.hpp"
#include "opencv2/imgproc.hpp"
#include "opencv2/highgui.hpp"
#include <iostream>
using namespace cv;
using namespace std;
int main()
{
Mat mat_src = Mat::eye(3, 4, CV_8UC1);
cout << "mat_src :" << endl;
cout << mat_src << endl;
cout << endl;
cout << "Rows : " << mat_src.rows << endl;
cout << "Cols : " << mat_src.cols << endl;
//注: mat_src.at<float>(y, x), 下标关系为: y-x
mat_src.at<float>(0, 2) = 2;
mat_src.at<float>(2, 0) = 4;
cout << endl;
cout << "mat_src :" << endl;
cout << mat_src << endl;
return 0;
}
Matlab Images
From https://ww2.mathworks.cn/help/images/images-in-matlab.html
An image composed of 200 rows and 300 columns of different colored dots would be stored in MATLAB as a 200-by-300 matrix.