Corner detection based on modified Hough transform

In this paper, the problem of detecting corners is simplified into detecting simple lines (straight lines that pass through the coordinate origin) in a local coordinate system. As simple lines can be expressed using only one parameter, Hough transform can detect them quickly. Other edge detectors have some problems when marking edge points around corners. Instead of using a general global edge detector, we detect edge points locally based on both gradient magnitude threshold and gray level analysis. The process is dynamic and can provide correct edge points for Hough transform. Gradient direction is used to reduce the effect of noise and speed up the algorithm. Experiments proved that our new algorithm works well over most images, and is fast enough for real-time applications. (C) 2002 Published by Elsevier Science B.V.