Analysis of spatial transform motion estimation with overlapped compensation and fractional-pixel accuracy
Fernando J. P. Lopes, M. Ghanbari · IEE Proceedings - Vision Image and Signal Processing · 1999
The authors investigate how the performance of spatial transforms motion estimation can be significantly improved by incorporating overlapped compensation and fractional pixel accuracy. An overlapped spatial transformation (OST) motion model is developed, which successfully addresses the inability of the conventional block matching technique to compensate for complex motion and inside-block motion field discontinuities. Simulation results show that the motion compensated prediction error of this method is reduced by 1.1dB, compared with the conventional overlapped block matching motion estimation, for the same generated motion vectors overhead. To improve the performance, the overlap must be used in both the motion estimation and compensation processes. Further improvement can be obtained using half-pixel precision motion vectors. However, this improvement is comparatively less than the gain of conventional block matching from a half-pixel search.