适于PCT编码的低内存离散小波变换

Low-Memory Discrete Wavelet Transform for PCT-Based Image Coding

基于常用的双正交对称DWT滤波器组的紧支撑性给出了一种适于基于PCT(Parent-Children Tree)的图像编码的低内存DWT实现方法—Stripe-Based DWT(SBWT).该方法生成与全局DWT相同的子带系数,且内存需求仅依赖于图像宽度、DWT滤波器组及分解层数.SBWT直接生成PCT,基于PCT的图像编码器与SBWT之间无需中间缓存.当采用CDF 9/7小波及5层分解时,相对于LBWT及Memory-constrained WT,SBWT的系统时延减小了31行,内存需求分别减小了18.4%与17.9%.

Based on the compact support property of popular DWT filters, a low-memory implementation of DWT called the Stripe-Based DWT（ SBWT）is proposed, which produces the same subband coefficients as the global implementation of DWT. Additionally, the production of subband coefficients Iends itself to PCT-based image coders in that no intermediate buffeting is needed between the SBWT and the coders.When coupled with PCT-based image codec＇s and 5-level decomposition with the CDF 9/7 filter bank,the overall memory reductions are 18.4% and 17.9% compared with the line-based DWT （LBWT） and the memoryconstrained WT, respectively.