OpenCV groupRectangles - getting grouped and ungrouped rectangles

Question

I\'m using OpenCV and want to group together rectangles that have significant overlap. I\'ve tried using groupRectangles for this, which takes a group threshold

Answer 1

The solution I ended up going with was to duplicate all of the initial rectangles before calling groupRectangles. That way every input rectangle is guaranteed to be grouped with at least one other rectangle, and will appear in the output:

int size = rects.size();
for( int i = 0; i < size; i++ )
{
    rects.push_back(Rect(rects[i]));
}
groupRectangles(rects, 1, 0.2);