HEVC 帧内预测编码快速判决算法分析

摘要

The emerging international standard of HEVC is a successor to H.264 /AVC,it achieves the highest coding efficiency compared with previous standards due to HEVC adopts flexible coding unit structure and a large number of intra prediction modes,but also involves a very high computational complexity because HEVC traversals all the possible depth levels and prediction modes to find the one with least rate distortion cost using Lagrange multiplier.In order to alleviate the encoder computation load,many researchers at home and abroad propose a lot of fast intra prediction algorithms which result in significant acceleration effect with slight per-formance degradation.This paper summarizes these algorithms from CU size decision and intra mode decision respectively,elaborates in detail their working principle and analyzes their characteristics and train of thought.%新兴的国际标准 HEVC 是 H．264／AVC 的继任者，由于采用了灵活多变的编码单元结构和大量的帧内预测模式，和以往的标准相比，HEVC 取得了最高的编码效率，但同时也带来了极大的计算复杂度，这是因为 HEVC 需要遍历所有可能的 CU 深度层次以及预测模式来找到率失真代价最小的编码模式。为了减轻编码器的计算负荷，国内外很多研究者提出了大量帧内预测算法，这些算法取得了明显的加速效果而只有轻微的性能损失。从 CU 尺寸和帧内模式两方面的快速判决总结了这些算法，详细阐述了它们的工作原理，分析了它们的特点以及采用的思路。