改进的LZSS算法在电子邮件系统中的应用  

Application of Improved LZSS Algorithm in E-mail System

作　　者：王雷[1] 许颖[2] 任光[1] 

机构地区：[1]大连海事大学自动化与电气工程学院,辽宁大连116026 [2]吉林大学计算机科学与技术学院,长春130012

出　　处：《吉林大学学报（信息科学版）》2005年第3期331-336,共6页Journal of Jilin University（Information Science Edition）

摘　　要：在海上专用电子邮件系统中,对邮件进行压缩可以有效节省通信费用。采用预先加载字典,精简压缩代码对中每个分量的表示方法,以及减少算法复杂度等方法对LZSS算法进行了改进,并且将其应用于电子邮件系统。在实际环境下的测试结果证明,改进后的压缩程序是有效的,邮件大小相对于压缩前有了明显改变。根据文件类型的不同,压缩比相应不同:对于中英文混合的文档类型文件,压缩比一般为0.4～0.6;对于长文件的压缩,算法表现更好。与标准LZSS压缩算法相比,压缩比提高率在3%到20%不等。在邮件收发的过程中,比未压缩前节省通讯费用40%～60%,且缩短了收发时间。In the E-mail system used on ships, the cost of the communication may be saved by the compression of the emails. Some methods such as loading dictionary, simplifying each element of compressed pair-code and reducing complexity of the algorithm are used in this thesis to improve LZSS, and applied the improved algorithm in Email system. Ameliorated compression program is validated efficiently by testing in actual environment. The size of compressed mail can be obviously reduced. According to different file types, the compression ratio is different. For the documents that mixed Chinese words and English letters, its compression can reach 0\^4~0\^6. In larger files the algorithm can do better work. Compared with standard LZSS compression algorithm, the improved algorithm has increased in compression ratio universally, from 3% to 20%. During receiving and sending mails, it can save 40%~60% communication cost and also reduce the time of sending and receiving.

关 键 词：LZSS算法 字典编码 数据压缩 电子邮件传送 

分 类 号：TP274[自动化与计算机技术—检测技术与自动化装置] TP18[自动化与计算机技术—控制科学与工程]