Performance improvements to the Hough transform

The paper describes a new algorithm for the Hough transform, the combinatorial Hough transform, an improvement to the Hough space accumulator which gives greater resolution for a fixed size, and a new method for detecting line end points using the transform. These are described separately and implemented together to give a new algorithm with improved resolution. Also a method for the performance analysis of Hough transforms is introduced and exercised on the new algorithms, comparing their error performance with that of the standard Hough transform algorithm. It is found that the new algorithm with the parameter space improvements offers some real advantages over the standard and combinatorial algorithms, though this is dependent on the precise details of the implementation. The error analysis procedure is described in some detail and its effectiveness is discussed together with desirable enhancements