How to detect concentric squares?
I have vector of approximated 4-point closed contours. How I can determine that some of them are concentric?
add a comment
I througth about it. But if view angle is too big squares turn into quads and can not be decribed by RotatedRect. But I'll try and let you know.
you have also fitEllipse, but it returns RotatedRect too. (Anyway, what do you mean by quad?)
Worked well for me! To compare whether two contours are nested, and to find the biggest one:
- minAreaRect(); for both contours
- pointPolygonTest() for each contour and the other contour's center
- If the signs of both pointPolygonTest() calls are positive, they are concentric
- the outermost contour has the largest area, compute with contourArea()
