Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí sinh học đề tài : An improved EZBC algorithm based on block bit length | Wang et al. EURASIP Journal on Advances in Signal Processing 2011 2011 84 http content 2011 1 84 o EURASIP Journal on Advances in Signal Processing a SpringerOpen Journal RESEARCH Open Access An improved EZBC algorithm based on block bit length Renlong Wang 1 Shuangchen Ruan1 Chengxiang Liu1 Wenda Wang2 and Li Zhang3 Abstract Embedded ZeroBlock Coding and context modeling EZBC algorithm has high compression performance. However it consumes large amounts of memory space because an Amplitude Quadtree of wavelet coefficients and other two link lists would be built during the encoding process. This is one of the big challenges for EZBC to be used in real time or hardware applications. An improved EZBC algorithm based on bit length of coefficients was brought forward in this article. It uses Bit Length Quadtree to complete the coding process and output the context for Arithmetic Coder. It can achieve the same compression performance as EZBC and save more than 75 memory space required in the encoding process. As Bit Length Quadtree can quickly locate the wavelet coefficients and judge their significance the improved algorithm can dramatically accelerate the encoding speed. These improvements are also beneficial for hardware. PACS Keywords block bit-length zeroblock EZBC Quadtree DWT 1. Introduction At present the typical embedded wavelet-based image coding methods includes Embedded Zerotree Wavelet coder EZW 1 proposed by Shapiro Set Partitioned in Hierachical Tree SPIHT 2 proposed by Said etc. Set Partition Embedded block algorithm SPECK 3 proposed by Asad Islam Embedded Block Coding with Optimal Truncation EBCOT 4 used in JPEG2000 5 and Embedded ZeroBlock Coding and context modeling EZBC 6 proposed by Shih-Ta Hsiang etc. Among these algorithms EZW and SPIHT were based on the local characteristic in spatial-frequency domain of wavelet transform. They utilized the similarity of wavelet coefficients of the same spatial location in
