H.264引入帧内预测并采用拉格朗日率失真优化(RDO)技术来选择最佳帧内预测模式,提高I帧的编码效率,但也大大增加了编码的计算复杂度。为了降低计算复杂度,根据帧内预测算法特征提出了一种基于像素方向相关性的帧内预测模式快速选择算法。实验结果表明,该算法在保证图像质量和比特率大致不变的前提下,极大地降低了帧内预测编码的计算复杂度。

H.264 introduces intra-prediction coding and uses Lagrangian rate-distortion optimization(RDO) technique to decide the best intra-coding mode.Although the intra-prediction greatly improves the intra-coding efficiency,it enormously increases the computational complexity.In order to decrease the computational complexity of the algorithm,a fast algorithm for intra-prediction mode decision based on pixel's directional relativity is presented in this paper.Experimental results show that compared with the original intra-prediction coding scheme,the proposed algorithm reduces the computational complexity of intra-prediction coding dramatically with only trivial loss of PSNR and increment of bite-rate.