A Fast Mode Decision Algorithm for H.264/AVC Intra Prediction

Fast Mode Decision in H.264/AVC

“…Compared with the standard, the algorithm can achieve around 76% time savings with an average of 0.17 dB PSNR decrease and 2.83% bit rate increase. Authors also claim that their scheme outperforms the work in (Pan, 2003) in terms of PSNR (0.05dB increase), bit-rate (0.66% decrease) and encoding time savings (around 43% savings).…”

“…So some macroblocks which are homogeneous could belong to a specific subset {MODE_16*16, MODE_16*8, MODE_8*16} of modes, and do not need to be motion estimated for the rest of the modes. The authors use the edge map computed in the fast intra mode decision technique of (Pan, 2003) to decide which macroblocks belong to homogeneous regions. If the current macroblock is homogeneous, its mode belongs to the set {MODE_16*16, MODE_16*8, MODE_8*16}, otherwise all modes are tested.…”

“…In (Meng, 2003;Zhang, 2004;Pan, 2003;Fu, 2004;Tsai, 2008;Yang, 2004;Cheng, 2005) fast intra mode decision is based on pixel domain analysis. B.…”

“…If the most probable intra mode type is INTRA16*16 and the Rate distortion cost of the best INTRA16*16 is negligible, the INTRA4*4 modes will not be examined. Compared with Pan (2003) this work reduces computation time by a factor of 2 to the expense of very small RD performance degradation.…”

“…Between one and four modes with the smallest energy plus the most probable mode are selected as the candidate modes for the current block. Compared with Pan (2003) the average time savings are increased and the RD performance is improved.…”