像素级运动矢量场边信息生成算法

摘要

The quality of side information generated by a decoder has a significant influence on the Rate-Distortion ( RD) performance of distributed video coding (DVC) codec. In order to improve the RD performance of a DVC by improving the quality of side information, a new side information generation algorithm based on pixel level motion vector field (SCPMVF) is proposed. First, the accurate pixel level motion vector fields (PMVF) of the forward and backward key frames are acquired respectively by motion estimation; then, the motion vectors of all pixels in the Wyner-Ziv frame are selected; finally, the high quality side information is obtained by interpolation. A new search range determination method based on the difference of SAD (sum of absolute difference) and a new pixel level MV (motion vector) selection method is proposed in the SGPMVF. Experimental results show that up to 1.45 dB gain for the side information and about 0.3-? 0.7 dB better RD performance can be achieved for fast motion sequences, while remaining the same rate and coding complexity.%在分布式视频编码(DVC)中,解码端生成的边信息的质量对整个系统的率失真(RD)性能有着重要影响.为了提高边信息的质量,进而提升DVC系统的RD性能,提出一种基于像素级运动矢量场的边信息生成算法(SGPMVF).首先,通过运动估计分别获得前后两关键帧的像素级运动矢量场；然后,为Wyner-Ziv帧的每个像素选择合适的运动矢量；最后,通过帧间内插得到高质量的边信息.算法中提出基于SAD(绝对误差和)差值的搜索范围确定方法与像素级运动矢量选择方法.实验结果表明,对于快速运动的序列,该算法在不增加编码复杂度和码率的情况下使边信息的PSNR最大提高1.45 dB,并使DVC系统的RD性能提高0.3～0.7 dB.