基于边缘方向直方图的H.264帧内预测快速算法

Fast Algorithm for Intra-Prediction Mode Selection in H.264/AVC Based on Edge Direction Histogram

H.264/AVC是最新的视频编码标准,和以往的标准相比,它具有更高的压缩性能。H.264/AVC采用了非标准方法率失真优化(RDO,Rate Distortion Optimization)技术,提高编码性能的同时也使得计算复杂度大大增加,难以适应实时性要求较高的场合。为了降低帧内预测模式选择的复杂度,在Pan算法的基础上提出了快速模式选择新算法。对Pan的基于边缘方向直方图的快速算法进行了改进;同时,结合色度预测模式与亮度预测模式的相关性,以及Intra16×16与Intra4×4的相关性,从而降低了模式选择的计算复杂度。实验结果表明,该方法在PSNR和码率基本不变的情况下,编码时间大大缩短。

H. 264/AVC video coding standard aims to enable to significantly improve compression performance compared to all existing video coding standards, In order to achieve that, a robust rate-distortion optimization （RDO） technique is employed to select the best coding mode. As a result, the complexity of computation increase drastically, which makes it difficult for practical applications such as real time video compression. Presents a fast mode selection for intra- prediction based on Pan algorithm to reduce complexity . First, Pan＇ s fast algorithm is improved; meanwhile, joining the relation of chroma predictive mode and luminance predictive mode, besides the relation of Intra - prediction 16 × 16 and 4 × 4 blocks. Experiment result shows that the algorithm increases the speed of intra - prediction with negligible loss of peak signal to noise ratio.