C++ opencv image editing - opencv

Question

I want to provide center coordinates of small square i.e (5,5)[small square is 10x10] to be placed on (8,8) coordinates of larger square of 20x20.
to get this image result:

Answer 1

try this, I didn't test it though, so please comment if it doesn't work and I'll try to fix it =)
cv::Mat placeImageInImage(cv::Point center, cv::Mat src, cv::Mat dst_orig)
{
cv::Mat dst = dst_orig.clone();
cv::Rect targetRect = cv::Rect(center.x-src.cols/2, center.y-src.rows/2, src.cols, src.rows);
cv::Rect srcRect = cv::Rect(0,0,src.cols, src.rows);
cv::Rect dstRect = cv::Rect(0,0,dst.cols, dst.rows);
cv::Rect roi = targetRect & dstRect;
srcRect.width = roi.width;
srcRect.height = roi.height;
// didnt test, maybe swap the order:
srcRect.x += roi.x - targetRect.x;
srcRect.y += roi.y - targetRect.y;
src(srcRect).copyTo(dst(roi));
return dst;
}
using this code to test:
int main(int argc, char* argv[])
{
cv::Mat input = cv::imread("C:/StackOverflow/Input/Lenna.png");
cv::Mat input2;
cv::resize(input, input2, cv::Size(256, 256));
cv::Mat result = placeImageInImage(cv::Point(256, 256), input2, input);
cv::imshow("input", input);
cv::imshow("result", result);
cv::waitKey(0);
return 0;
}
I get: