摘要： H.264帧内编码通过空间预测减小变换编码输入值的大小，提高编码压缩性能。由于块编码总按照从左往右和从上往下的顺序，帧内预测可选的参考像素限制于块的左边和上边，因此预测结果不理想。该文提出一种基于宏块内部灵活的子块编码顺序的Intra 4×4预测编码算法，自适应地选择最佳预测参考像素集，同时对空间预测模式进行了改进。通过有限的子块分组和子块顺序选择，可以实现宏块内部编码最优化。仿真试验表明，和H.264相比，该算法可以取得平均0.4 dB 的PSNR编码性能增益。

关键词: 帧内预测, 灵活的子块编码顺序, 参考像素集

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

中图分类号: 

• TN919