一种新的多假设运动补偿预测算法
摘 要
多假设运动补偿预测(multi hypothesis motion compensated prediction,MHMCP)算法目前只应用于H264/AVC视频编码标准中B帧的双向预测模式,因为其需对多个运动矢量及参考帧信息进行编码,而且其最终预测信号由前/后向参考帧中的最佳运动补偿信号(假设值)求和取平均值获得,精确性不够。针对MHMCP传统算法的缺陷,提出了一种新的MHMCP算法,即在保持当前最佳编码模式不变的基础上,首先通过加入前/后向运动矢量导出搜索模式来进行假设值的局部优化,并对多假设值进行
关键词
A New Multi hypothesis Motion compensated Prediction Algorithm
() Abstract
Multi hypothesis motion compensated prediction has been used as bi directional prediction mode in B picture of the H264/AVC video compression standardThe optimal motion compensated prediction signal,named hypotheses,is composed of blocks in both forward and backward 〖JP2〗reference pictures,which are simply added and averaged to synthesize the final prediction signalIn the original algorithm,more than one motion vector and reference information has to be encoded and the accuracy of motion compensated prediction is still insufficientTo overcome these disadvantages,a new rate distortion optimization 〖JP〗based MHMCP algorithm is proposedAfter the optimal MBs encoding mode has been obtained by motion estimation and mode decision procedure,bi directional motion search with iterative local motion vector refinements will be startedAt the same time,two extra mv tracking modes which need not to encode additional side information will be examined,accompany with adaptive hypothesis coefficients adjustmentExperimental results show that not only the energy of the residual signal can be decreased but also the quality of the motion compensated prediction signal can be improvedTherefore better R D performance can be achieved by the proposed algorithm
Keywords
multi hypothesis motion compensated prediction(MHMCP) rate distortion optimization H.264/AVC motion estimation
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