MPEG-4中四运动向量运动估计的预先排除算法

Pre-excluding Algorithm of the 4-MV Motion Estimation in MPEG-4

为了提高运动补偿的效率,在M PEG-4压缩编码中采用了变尺寸块(8x8和16x16)运动估计算法,这种算法复杂度高,是影响M PEG-4编码整体效率的关键。本文研究了M PEG-4中率失真框架下四运动向量运动估计的预先排除算法(4M VPE),在已知一个宏块的16x16运动向量的情况下,通过简单的计算和判断,排除相当一部分宏块不再需要4次8x8块运动估计(四运动向量运动估计),从而简化整个编码过程。实验表明,4M VPE算法使变尺寸块运动估计的速度得到了很大的提高,而峰值信噪比(PSNR)则下降很小。

For improving coding efficiency,variable-size block （8×8 and 16×16）motion estimation is used in MPEG-4 video coding.It is very computing intensive and influences the efficiency of MPEG-4 video coding heavily.An algorithm is presented that excludes quite a few macroblocks from 8×8 block motion estimation （4MVPE）.The algorithm estimates that if it is necessary to do the 8×8 block motion estimation by simple computations of 16×16 SAD and motion vectors in MPEG-4 using the rate-distortion optimization method,when the 16×16 motion vector is present.The experimental results show that the proposed algorithm 4MVPE accelerates the variable-size block （8×8 and 16×16）motion estimation greatly with a very low PSNR drop.