Improved Intra 4×4 Prediction Algorithm for H.264
Wei Hu, Lin Zheng-hui · Jisuanji gongcheng · 2008
【Abstract】In H.264, intra prediction is employed to reduce energy of prediction error. The order of Intra block encoding is from left to right horizontally and from top to bottom vertically, so the prediction reference pels can only appear on the left side or upside of the current block, without ideal predicted result sometimes. In this paper, a new Intra 4×4 prediction algorithm based on flexible order of subblocks encoding is introduced, with improved prediction modes and a new set of reference pels. It realizes RD optimization of intra Macroblock(MB） encoding by mode decision of subblock grouping and subblock ordering. Experimental results show that compared with the standard intra prediction mode of H.264, this method can gain 0.4 dB of PSNR averagely. 【Key words】intra prediction; flexible subblock encoding order; set of reference pels