Pre-processing difference between Hough Line Transform and Hough Circle Transform

asked 2013-07-11 16:52:27 -0500

Calden gravatar image

I have an application in which I would like to use both the Hough Line Transform and the Hough Circle Transform. As far as I understand (from reading the Hough Line Transform Tutorial and the Hough Circle Transform Tutorial), the Hough Line Transform functions (HoughLines and HoughLinesP) do not implicitly include any edge-detection pre-processing, and thus one should first explicitly include that code (such as with Canny or Sobel functions). However, the Hough Circle Transform function HoughCircles seems to implicitly include a Canny detector in its operation.

My question is why is there this disparity? Is there any way to turn off the internal Canny detector in HoughCircles? Since I plan to use both detection methods, it seems like it would be much more efficient if I could perform edge detection a single time on the image and then pass that pre-processed image to both detectors rather than rely on an internal detector in HoughCircles. Processing time is an issue with my application, so cutting out unnecessary calculations would be desirable.

edit retag flag offensive close merge delete