基于H.26L的精细度可伸缩视频编码

提出了一种基于H．26L精细度可伸缩(fine granularity scalability)视频编码方案，称为EFGS-H．26L。在该方案中，以MPEG-4的FGS为基础构造了一种新的可伸缩结构(EFGS，enhanced fine granularity scalability)，在EFGS结构中，基本层采用H．26L编码，增强层采用类似于JPEG2000的基于上下文的位平面编码。由于H．26L优良的编码性能，使得基本层的编码效率大大提高，为了提高增强层的编码效率，首先把残余图像按子带的顺序重新排列，这样就可以利用子带系数的相关性来实现冗余信息消除。JPEG2000标准中的EBCOT算法已经被证明是非常高效的位平面编码方法，所以对重排后的DCT系数采用一种类似于JPEG2000的基于上下文的位平面编码方法。实验结果证明，在高比特率时，本文提出的精细度可伸缩编码方案编码效率比MPEG-4中的FGS提高3．0dB左右。

H.26L based fine granularity scalable video coding

This paper presents a fine granularity scalable video coding scheme based on H.26L (EFGS-H.26L). Building upon the MPEG-4 FGS, a new scalable framework is designed, referred to as EFGS (enhanced fine granularity scalability). In the EFGS framework, the base layer is encoded with H.26L, and the enhancement layer is encoded with a kind of context bit-plane coding algorithm like JPEG2000. The efficiency of the base layer coding is significantly improved because H.26L is used. In order to improve efficiency of the enhancement layer coding, we firstly reorder the residue coefficient into subbands. This enables us to better exploit the correlations of the coefficients. Then a kind of context-based bit-plane coding algorithm is used to eliminate the intra correlations. Experiments show that the coding efficiency of the proposed scheme is about 3.0 dB compared with MPEG-4 FGS at high bit rate.