I am detecting ellipses and tried different methods,
I tried Hough Circle and it is detecting only perfect circles
I tried Fit Ellipse after applying it on Find Contours and it is doing pretty well.
I came across Fast Radial Transform and i was wondering would it detects perfect circles only or it will also detect Ellipses?
Thanks
Probably the radial transform (Loy&Zelinsky) is not the best way to detect ellipses.
From the definition of the transform, every pixel affects only the pixels along the gradient vector in the current pixel and to a given distance n. This is perfect to detect circles, as the radius vector is always perpendicular to the contour and the distance to the center of the circle is constant (=radius).
However in the case of ellipses, the contour isn't perpendicular to the radius, and the radius varies also; so it won't give a single bright pixel in the accumulator space.
Maybe with some adaptations you could obtain some results (by varying the sigma parameter) , but I think there are better suited algorithms for ellipse detection.
Asked: 2018-05-16 05:13:00 -0600
Seen: 375 times
Last updated: May 16 '18
"I tried Hough Circle and it is detecting only perfect circles" NO
FastRadialTransform can you give a link in opencv doc?