【摘要】 提出了一种 SPIHT(set partition in hierarchical trees)编码和分块运动补偿相结合的视频压缩算法 ,适用于视频监控、视频会议、可视电话等许多视频图像的运动范围较小的场合。该算法具有如下 3个特点 :一是采用基于最低码率的自适应算法 ,实现了波动带宽下编码端和解码端参考帧的一致性 ;二是采用对预测残差帧的小波压缩编码 ,进一步增加了残差图的零像素数量 ,从而获得了更高的压缩比 ;三是采用了 SPIHT多级树集合分裂算法 ,实现了码率的可扩展性 ,能适应波动带宽和不同性能接受端的需要。运用本文提出的算法 ,能进一步提高视频编码的压缩比和解码复原质量。实验结果表明 ,本算法对于运动范围较小的视频序列 Akiyo,具有很高的压缩比和较好的复原质量 ,在 2 7kbps带宽下 ,压缩比可达 35 5∶ 1,相应的 PSNR(Y) =36 .33d B,PSNR(U) =4 0 .2 2 d B,PSNR(V) =4 2 .5 2 d B;对于运动范围较大的 Singer序列 ,本算法与 MPEG- 4校验模型相比 ,性能相差不大。此外 ,在最大码率下 ,本算法的 PSNR(Y)比 MPEG- 4校验模型平均提高约 4 .0 d B更多还原

【Abstract】 This paper presents a SPIHT(set partition in hierarchical trees) and Motion Compensation Based Rate Scalable Video Compression algorithm. We will refer to this new technique as the Scalable Adaptive Motion Compensated SPIHT (SAMCS) algorithm, which can be used in video surveillance, video meeting, etc. SAMCS has three characteristics: Firstly, it uses adaptive Intra/Inter block coding and the lowest rate based reference frame reconstruction to adapt to the various bandwidth; Secondly, it makes wavelet transform on prediction error frame (PEF) to create a lot of zero pixels and achieve much higher compression rate; finally, SPIHT is a fine scalable coding, so SAMCS can get scalable rate bitestream based on the lowest rate reference frame reconstruction, which is very appealing for network-oriented application. Experimental results show that, SAMCS has an excellent performance on compressing low-motion video. For example, the PSNRs of Akiyo’s three components(Y, U, V) are 36 33dB, 40.22dB and 42.52dB by SAMCS at 27kbps, and the compression rate is (355∶1). As to high-motion video, such as Singer, the performance of SAMCS is no better than MPEG-4 VM. What’s more, compared to MPEG-4 VM, the PSNRs of Y components is improved 4.0dB on the average at the highest bit-rate.更多还原