H.264 High Profile的帧内预测模式快速判决算法研究

H.264 High Profile Intra Prediction Mode Decision Algorithm

为降低H.264 High Profile帧内预测模式判决的复杂度,提出了2方面的改进:1)在模式判决的第1阶段即块大小判决,提出了1种自适应阈值来排除不可能的块大小;2)在模式判决的第2阶段即预测模式判决,利用8×8模式判决的最优模式及最可能模式和SATD值来减少4×4的待选模式。与JM参考软件的对比结果表明,在不影响图像质量的前提下,提出的算法能减少平均61%的时间。

To reduce the time complexity of H. 264/AVC High Profile, two improvements are proposed： 1 ） In the first phase of mode decision, block size decision, an adaptive thresholding is developed to eliminate impossible block size;2） In the second phase, prediction mode selection, we exploit SATD value, the best mode of intra 8x8 and the most probable mode to reduce the number of the candidate modes. Performance comparison with original JM shows that the proposed algorithm achieves a reduction of 61% computational complexity on average with a little PSNR loss and bit rate increasement.