Three Dimensional Hough Space

Question

Im searching for radius and the center coordinates of circle in a image. have already tried 2D Hough transform. but my circle radius is also a unknown. Im still a beginner to Computer vision so need guild lines and help for implementing three dimensional hough space.

Answer 1

You implement it just like 2D Hough space, but with an additional parameter. Pseudo code would look like this:

for each (x,y) in image
     for each test_radius in [min_radius .. max_radius]
         for each point (tx,ty) in the circle with radius test_radius around (x,y)
             HoughSpace(tx,ty,test_radius) += image(x,y)