The probabilistic Hough transform uses random sampling instead of an accumulator array. In this approach the number of random samples r, is not specified in the OpenCV call, but is an important hidden parameter. If there are n feature points in an image then what is the running time of the probabilistic Hough transform in big O notation.
If we wished to find an ellipse using the Hough Transform, which of the two approaches is most practical (Standard HT, or probabilistic HT).