【摘要】 考虑到三维小波变换系数沿时间频带和空间频带的统计特征变化不同 ,首先定义了一种分级时 空小波树 ,以有效利用帧内相关性与帧间相关性的差异 ,提高对时间低频子带内的空间高频子带的小波系数编码效率 ,然后将它应用到修正的三维SPIHT (SetPartitioningInHierarchicalTree)编码算法中 ,进而提出了一种改进的三维小波视频编码器 .低比特率的测试结果表明 ,改进后的三维SPIHT视频编码器性能上优于H .2 63.同时 ,该编码器也具有渐近式传输所期望的嵌入特性 ,可以实现比特率精确控制 ,满足定速率传输视频应用的需要 .更多还原

【Abstract】 Considering the differences of statistical property varying across subbands in temporal direction and spatial direction,an optimized scalable temporal-spatial wavelet tree is firstly defined to capture the diffecences of correlation between intra-frame,inter-frame improveing coding efficiency of the temporal-low spatial-high subbands. Then an improved 3D-SPIHT video coder is developed based on the scalable temporal-spatial wavelet tree as well as a modified 3D-SPIHT coding algorthm. Simulations at low bit-rate yield the prior performance to H.263 Coder. The coder has the desired embedded feature for progressive transmission and precise rate control for constant bit-rate traffic application.更多还原