基于JPEG2000的一次性扫描、高效编码算法的研究  

Study on one scanning and high-efficient encoding algorithm based on JPEG 2000

作　　者：张宏伟[1] 刘正光[1] 陈红新[1] 

机构地区：[1]天津大学电气与自动化工程学院,天津300072

出　　处：《计算机应用》2005年第5期1069-1071,共3页journal of Computer Applications

基　　金：天津市自然科学基金资助项目(023601011)

摘　　要：JPEG2000的算法的复杂性限制了它的优势的发挥。EBCOT是JPEG2000系统中占运算时间最多的组成部分,它对每个位平面进行三次扫描、进行三个编码通道的编码操作,浪费了大量的运算时间。针对这种情况,文中应用一次扫描完成三个编码通道编码操作的算法对其进行改进,在一次扫描过程中对位平面的所有系数进行编码。针对此算法引出的问题:首先,应用两个重要性状态变量代替原算法中的一个重要性状态变量;其次,采用“对称映射”形成上下文;最后,对三个编码通道的MQ编码器状态和上下文状态分别进行存储。这样三个编码通道可以顺序编码而不互相干扰,大大减少了运算时间,但仍保持了JPEG2000的优异性能。Due to the high complexity of computation, JPEG2000 cannot be used in many conditions. As an important part of JPEG2000, EBCOT algorithm performs the scanning 3 times in each bit plane and codes all coefficients in 3 coding passes, wasting lots of operation time. A scanning algorithm was introduced and all the coefficients of one bit plane could be coded in one scanning. Firstly, to deal with the problems caused by this algorithm, two significance state variables rather than a single variable were introduced, Secondly, the 'stripe-causal' mode was used to form the context. Finally the states of MQ coder and context were stored separately according to 3 coding passes. Thus one scanning method could improve the coding efficiency greatly while keeping the excellent performance of JPEG2000.

关 键 词：EBCOT 重要性状态 编码通道 上下文 

分 类 号：TN919.81[电子电信—通信与信息系统]