Copy an cv::Mat inside a ROI of another one

Question

I need to copy a cv::Mat image (source) to an ROI of another (Destination) cv::Mat image.

I found this reference, but it seems that it does

Answer 1

OpenCV 2.4:

src.copyTo(dst(Rect(left, top, src.cols, src.rows)));

OpenCV 2.x:

Mat dst_roi = dst(Rect(left, top, src.cols, src.rows));
src.copyTo(dst_roi);

Answer 2

In addition or correction to above answers, if you want to copy a smaller region of open Mat to another Mat, you should do:

src(Rect(left,top,width, height)).copyTo(dst);

Answer 3

Did work for me this way:

Mat imgPanel(100, 250, CV_8UC1, Scalar(0));
Mat imgPanelRoi(imgPanel, Rect(0, 0, imgSrc.cols, imgSrc.rows));
imgSrc.copyTo(imgPanelRoi);

imshow("imgPanel", imgPanel);
waitKey();

I am using Opencv 2.4.9 Based on Andrey's answer.