基于H.264的帧内自适应预测算法

An Adaptive Prediction Intra-frame Algorithm Based on H.264

为了满足实时应用的需求,有必要对H.264帧内预测部分进行合理的优化。目前,研究人员对4*4亮度块所做的优化工作较多,而针对16*16亮度块和8*8色度块的优化并不常见。这里提出一种自适应帧内预测算法,该算法依据4*4亮度块,16*16亮度块以及8*8色度块最佳预测模式之间的相关性,根据16个4*4亮度块所选择的最佳预测模式来对16*16亮度块和8*8色度块的最佳预测模式进行快速预判。试验结果表明在几乎不影响编码质量的情况下,该算法以极小的计算量获得了显著的效率,可使16*16亮度块和8*8色度块最佳帧内预测模式选择的计算量分别下降65%和50%左右。

To meet the need of real-time application, a reasonable optimization on H. 264 intm prediction is essential. At present, research- ers have done lots of optimization work for 4 ＊ 4 luminance block,but the efforts on 16 ＊ 16 luminance block and 8 ＊ 8 chroma block seems to be not so common. Based on the best prediction mode correlation between 4 ＊ 4 luminance block, 16 ＊ 16 luminance block and 8 ＊ 8 chroma block,an adaptive algorithm was proposed. This algorithm can make fast mode decision for 16 ＊ 16 luminance block and 8 ~ 8 chroma block according to the best modes that the sixteen 4 ＊ .4 luminance blocks have selected. Experimental results demonstrate that the proposed algorithm obtains a remarkable efficiency with only a small amount of calculation. It makes the calculation for 16 ＊ 16 lumi- nance block and 8 ＊ 8 chroma block＇s optimal intra prediction mode selection drop respectively 65% and 50%, almost having no effect on the coding quality.