Automatic feature point extraction and tracking in image sequences for unknown camera motion

Abstract

An automatic ego motion compensation based feature detection and correspondence algorithm is presented. For image sequences taken from a moving camera, feature displacement over consecutive frames can be approximately decomposed into two components: the displacement due to camera motion, which can be compensated for by image rotation, scaling, and translation; and the displacement due to object motion and/or perspective projection. The authors introduce a two-step approach. First, the motion of the camera is compensated for by using a computational vision based image registration algorithm. Then consecutive frames are transformed to the same coordinate system and the feature correspondence problem is solved as though for a stationary camera. Feature points are detected using a Gabor wavelet decomposition and a local interaction based algorithm. Methods for subpixel accuracy feature matching and tracking are introduced. Experimental results on a real image sequence are presented. >