Joint block motion estimation in H.264/AVC

Traditionally, block-based motion estimation (ME) searches for the best motion vector (MV) for one block at a time based upon a pre-defined ME cost. The ME cost is often a function of the best MV and its predictor (MVP). In H.264/AVC, MVP of a block is calculated from MVs of its neighboring blocks in the past. Therefore, the ME decision of a current block is affected by the neighboring blocks in the past, and in turn, it also affects the ME results of the neighboring blocks in the future. In this paper, we propose a joint ME process that searches for the best MVs for a group of blocks, which takes the interdependence of MVs into account. The proposed method smoothes MV fields and improves coding efficiency.