A new image coding technique with low entropy using a flexible zerotree

作     者：Joo, S Kikuchi, H Sasaki, S Shin, J 

作者机构：Niigata Univ Dept Elect Engn Niigata 9502181 Japan Dongguk Univ Dept Elect Engn Joong Gu Seoul 100715 South Korea 

出 版 物：《IEICE TRANSACTIONS ON COMMUNICATIONS》 (电子情报通信学会汇刊，英文版，B:通信)

年 卷 期：1998年第E81B卷第12期

页      面：2528-2535页

核心收录：

学科分类：0810[工学-信息与通信工程] 0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 

主　　题：image compression wavelet transform zerotree coding entropy coding 

摘      要：A zerotree image-coding scheme is introduced that effectively exploits the inter-scale self-similarities found in the octave decomposition by a wavelet transform. A zerotree is useful for efficiently coding wavelet coefficients;its efficiency was proved by Shapiro s EZW. In the EZW coder, wavelet coefficients are symbolized, then entropy-coded far further compression. In this paper, we analyze the symbols produced by the EZW coder and discuss the entropy for a symbol. We modify the procedure used for symbol-stream generation to produce lower entropy. First, we modify the fixed relation between a parent and children used in the EZW coder to raise the probability that a significant parent has significant children. The modified relation is flexibly modified again based on the observation that a significant coefficient is more likely to have significant coefficients in its neighborhood. The three relations are compared in terms of the number of symbols they produce.