摘要
根据视频对象形状的特点 ,提出了一种新的视频对象形状编码方法 .这种方法仍然属于基于位图的方法 ,但是具有很好的可扩展性和压缩效率 .这种方法的核心是Zh变换 .利用Zh变换可以把表示视频对象形状的二值位图分解为一系列较小的二值位图 .这些小位图从粗到精地描述了视频对象的形状 ,这使得本方法具有很好的可扩展性 .压缩效率的提高来自以下两个方面 :(1)通过设置变换终止条件 ,可以自动标记位图中远离对象边缘的块 ;(2 )采用基于上下文的算术编码方法编码变换后的小位图 ,由于变换后的数据之间存在较强的相关性 ,算术编码器可以根据已经编码的数据更准确地预测下一个被编码位 .
According to the characteristics of video object shape, a new method for video object shape coding is presented which belongs to bitmap-based methods, but has good scalability and coding efficiency. The kernel of this method is Zh-transform. Using Zh-transform, the binary bitmap which represents the shape of video object is decomposed into a sequence of small binary bitmaps. These small bitmaps describe the shape from coarse granularity to fine granularity, so this method based on Zh-transform has good scalability. Coding efficiency is enhanced by the following two facts: (1) The blocks far from object border can be marked automatically by setting the termination condition of Zh-transform. (2) The small bitmaps are coded by CAE encoder. Because of the strong correlation among the transformed data, the next bit to be coded can be predicted precisely using the coded bits.
出处
《计算机学报》
EI
CSCD
北大核心
2003年第7期813-818,共6页
Chinese Journal of Computers
