Copying Region of an Image to another Region in another Image

Question

I would like to do a very simple thing: copy an area inside an image into a new area in a new image. In the OpenCV 2.3 cheatsheet, they suggest the following solution:

"Example 3. Copy image ROI to another image with conversion"

Rect r(1, 1, 10, 20);
Mat dstroi = dst(Rect(0,10,r.width,r.height));
src(r).convertTo(dstroi, dstroi.type(), 1, 0);

My code is the following:

Mat frameO, frameS;

original >> frameO;
stabilized >> frameS;

Mat output(frameO.rows+40, frameO.cols*2+60, CV_32FC3);
output.setTo(0);            
Rect r(0,0, frameO.cols, frameO.rows);
Mat destROI = output(Rect(20,20, frameO.cols, frameO.rows));
frameO(r).copyTo(destROI);

I just want to copy the image frameO in output at the location Rect(20,20, frameO.cols, frameO.rows).
Anyone can tell me why this is not working?

Answer 1

Actually these commands were not working in OpenCV 2.3 but now the following works fine with the 2.4 release:

Mat frame1 = imread(nameReading1);

Mat output(frame1.rows*2, frame1.cols*2, frame1.type());
output.setTo(0);

frame1.copyTo(output(Rect(0, 0, frame1.cols, frame1.rows)));

This will copy frame1 in output as long as the type agree so be careful when you create output. frame1 will be copied in a ROI in output defined by Rect(0, 0, frame1.cols, frame1.rows).