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内蒙古自治区呼和浩特市赛罕区大学西街235号 邮编: 010021
作者机构:Texas Tech Univ Lubbock TX 79409 USA
出 版 物:《OPTICAL ENGINEERING》 (光学工程)
年 卷 期:2004年第43卷第10期
页 面:2395-2399页
核心收录:
学科分类:08[工学] 080401[工学-精密仪器及机械] 0804[工学-仪器科学与技术] 081102[工学-检测技术与自动化装置] 0811[工学-控制科学与工程] 0702[理学-物理学]
主 题:JPEG end-of-block marker binary arithmetic coding discrete cosine transform
摘 要:In JPEG image compression algorithms, an entropy coder encodes an end-of-block (EOB) marker for each discrete cosine transform (DCT) block. The well-known Huffman coder encodes one such marker for each block. However, the binary arithmetic coder, which provides greater compression but is not as well known, encodes several EOB tests, one after each nonzero ac coefficient of the block. We present a modification to the JPEG arithmetic coding algorithm to reduce the number of EOB tests. Our algorithm encodes two extra zero ac coefficients for a small percentage of blocks, but it encodes fewer EOB tests. As a result, we reduce the total image code size by about 1.4% on average. In this process, we also study the effectiveness of the DCT and statistical models of this coder. (C) 2004 Society of Photo-Optical Instrumentation Engineers.