On the performance of warping-based motion estimation

Warping-based motion estimation has been proposed in the literature to achieve higher video coding efficiency compared to conventional block-based motion estimation. This paper investigates the performance of warping-based methods at very low bit rates typical of mobile video communication applications. Simulation results show that despite their improvements over block-based methods, the use of warping-based methods in such applications may not be justifiable due to the huge increase in computational complexity. In fact, it is shown that similar, if not better, improvements can be obtained, at a fraction of the complexity, by simply augmenting basic block-based methods with techniques like subpel accuracy and overlapped motion compensation.