一种改进的H.264帧内预测模式选择算法

针对H.264帧内预测模式选择中失真估计不准确和计算量大的问题,提出一种改进的H.264帧内预测模式选择算法。该算法首先对像素的递归失真估计方法进行改进,较为准确地估计了多种帧内预测模式下的预测失真,然后利用相邻块预测模式的相关性预先筛除部分预测模式,降低了H.264中帧内预测的复杂度。与JM参考软件的对比结果表明,该优化算法能在保证很好的图像质量的同时,将帧内预测模式选择的时间减少60%以上,有效地提高了视频图像的编码效率和视觉质量。

An improved intra-frame prediction mode selection algorithm for H.261

To improve the distortion estimation accuracy and simplify the computational complexi-ty of intra-frame prediction mode selection for H.264,an improved Intra-frame prediction mode selection algorithm is proposed.A recursive optimal per-pixel estimate algorithm is modified to estimate the reconstructed distortion for various intra modes of H.264/AVC.The correlation be-tween neighboring blocks and neighboring direction prediction mode is then used to predict the in-tra-frame mode,which efficiently skip some unlikely prediction modes and reduce the complexity of intra-frame prediction mode selection.Compared with the mode selection algorithm in H.264 reference software,the improved algorithm can save more than 60% of the encoding time with a negligible coding performance loss.Experimental results show that the proposed algorithm can a-chieve better coding efficiency and image quality.