A new center-biased orthogonal search algorithm for fast block motion estimation

A new center-biased orthogonal search algorithm (CBOSA) for fast block-based motion estimation is proposed. The new algorithm uses a center-biased search point pattern, which is based on center-biased motion vector distribution characteristic of the real-world image sequences, for improving the performance of the conventional orthogonal search algorithm (OSA). Simulation results show that the proposed CBOSA performs better than the OSA and the well-known three-step search in terms of compensation errors and search points requirement. In addition, the CBOSA also reduces the worst case search points requirement of the center-biased search algorithms from 33 of the new three-step search and 27 of the four-step search to 15 search points.