Introduction to opencv (I): image reading and display

#include <opencv2/opencv.hpp>
#include <iostream>

using namespace cv;
using namespace std;

int main()
{
    
	Mat src = imread("D:/images/age_gender.jpg",IMREAD_GRAYSCALE);// The second parameter is optional , Display in color format by default 

	if (src.empty())
	{
    
		printf("Can't load image\n");
	}

	namedWindow("InPut",WINDOW_FREERATIO);
	imshow("InPut", src);
	waitKey(0);  // Unit millisecond  0 Unlimited waiting for user cases 
	destroyAllWindows();
}