Ultra-fast tracking based on zero-shift points

A novel tracker of so called zero-shift points (ZSPs) is presented. ZSPs are points where a dot product with a single period of a sinusoidal wave, both in horizontal and vertical directions, is equal to zero. Very efficient tracking and localization of ZSPs is possible as a consequence of the existence of the field of 2D shift vectors pointing toward them. A single point is tracked on average in less than 10 mu s on a standard notebook. When organized in a Multi-scale Flock (MSF), the ZSPs become a core of a robust, fast and accurate tracker. We demonstrated the applicability of the combination of MSF-ZSP with RANSAC based homography estimation on standard sequences reporting good tracking results. (C) 2012 Published by Elsevier B.V.