In opencv how do I copy and scale a greyscale image into another colour image

Question

I want to composite a number of images into a single window in openCV. I had found i could create a ROI in one image and copy another colour image into this area without any

Answer 1

I realised my problem was i was trying to copy a greyscale image into a colour image. As such i had to convert it into the appropriate type first.

drawIntoArea(Mat &src, Mat &dst, int x, int y, int width, int height)
{
    Mat scaledSrc;
    // Destination image for the converted src image.
    Mat convertedSrc(src.rows,src.cols,CV_8UC3, Scalar(0,0,255));

    // Convert the src image into the correct destination image type
    // Could also use MixChannels here.
    // Expand to support range of image source types.
    if (src.type() != dst.type())
    {
        cvtColor(src, convertedSrc, CV_GRAY2RGB);
    }else{
        src.copyTo(convertedSrc);
    }

    // Resize the converted source image to the desired target width.
    resize(convertedSrc, scaledSrc,Size(width,height),1,1,INTER_AREA);

    // create a region of interest in the destination image to copy the newly sized and converted source image into.
    Mat ROI = dst(Rect(x, y, scaledSrc.cols, scaledSrc.rows));
    scaledSrc.copyTo(ROI);
}

Took me a while to realise the image source types were different, i'd forgotten i'd converted the images to grey scale for some other processing steps.