Low complexity variable-size block-matching motion estimation for adaptive motion compensation block size in H.264

An efficient merge-based algorithm for variable-size block matching ME (motion estimation) to reduce the computation of block-size decision process in H.264 video encoder is proposed. Fixed-size 4 × 4 small blocks are used for the integer-pixel accuracy full search ME and several candidate MVs are reserved for each 4 × 4 blocks to determined if the neighboring blocks could be merge into other predefined block types or not. Simulation result shows the computational load of our method is significantly reduced than H.264 JM 7.3.