OpenCV selectROI() API

#include <opencv2/opencv.hpp>
#include <opencv2/tracking.hpp>
 
using namespace std;
using namespace cv;
 
int main (int argc, char **arv)
{
    Mat im = imread("image.jpg");
 
    Rect2d r = selectROI(im);
    Mat imCrop = im(r);
 
    imshow("Image", imCrop);
    waitKey(0);
 
    return 0;
}