Efficient intra-prediction mode selection for 4/spl times/4 blocks in H.264

In the upcoming H.264, intra-prediction for 4/spl times/4 and 16/spl times/16 blocks is used to compress I-frame. However, we need to choose one of the 9 prediction modes for each 4/spl times/4 block. The full search (FS) algorithm to select the mode is computationally expensive. In this paper, an efficient intra-prediction mode selection (EIPMS) method is proposed based on partial computation of the cost function, selective computation of highly probable modes, early termination, and variable threshold setting. The proposed EIPMS can reduce the complexity considerably while maintaining similar PSNR and bit rate.