Efficient Block Size Decision Algorithm for Intra Mode Decision in H.264/AVC Encoder

In H.264/AVC intra frame coding, the rate-distortion optimization (RDO) is employed to select the optimal coding mode to achieve the minimum rate-distortion cost. Due to a large number of combinations of coding modes, the computational burden of Rate distortion optimization (RDO) becomes extremely high in intra prediction. In this paper, we proposed an efficient intra block size decision that selects the appropriate block size for intra prediction, further proposed fast intra prediction algorithm which reduces a number of candidate modes required for RDO. Experimental results show that the proposed fast mode decision algorithm reduces the encoding time by about 68% with negligible loss of video quality.