文件的压缩与解压lzw算法解析与实现 大学论文.doc

文件的压缩与解压 ──LZW算法解析与实现 摘 要: 随着人们对数据的大量需求以及计算机使用时间的增加，计算机磁盘上的文 件越来越大，越来越多。如何让有限的磁盘空间容纳更多的数据成为需要解决的 问题。一方面，高速发展的存储技术以提高磁盘容量来解决这样的需求，但随着网络环境下数据传递的产生以及带宽的限制，大容量数据问题日益突出。在这两种需求的推动下，对数据压缩的需求产生了。人们可以将文件在不改变其本身的 条件下，将其以更小的占用空间存储，并且在需要的时候将文件恢复成原有的样 子，这就是压缩目的。本论文主要研究文件的无损压缩技术，并简要介绍了文件压缩的分类、几种常用的无损压缩格式和常用的压缩算法。运用LZW字典算法，使用Java 语言在Eclipse 环境下设计了使用LZW 算法对文件压缩与解压缩的实现程序。用户可以根据自己的需求，使 用此程序方便地对文件进行压缩或者解压缩操作。这里压缩的实质是数字变换，在多媒体信息中包含大量冗余的信息，把这些余冗的信息去掉，就是实现了压缩；解压是由于计算机处理的信息是以二进制数的形式表示的，因此压缩软件就是把二进制信息中相同的字符串以特殊字符标记来达到压缩的目的。 关键词：压缩；解压缩；LZW Abstract?：with the increasing?demand?of?the large amount of data?and the using time of computer,?computer?disk?file?is more and more big,?more and more.?How to make the?limited?disk space?to accommodate more?data becomes a?problem need to be solved.?On the one hand,?the rapid development of storage technology?to?improve disk?capacity?to address?such needs,?but with the?networkenvironment of data?transfer?generation and?bandwidth constraints,?the problem of large capacity?data?have become increasingly prominent.?In the promotion ofthese two kinds of?demand,?the need for data compression and decompressionproduced.?People can?file?without changing their?own condition,?be?in?a smaller storage space,?and?the?file to its?original?appearance?in time of need,?this is?the final compression.?Lossless compression?techniques?the thesis focuses on the research of?documents,?and the classification,?file compression?of several commonly used?lossless compression?formats and?commonly used compression algorithms?are briefly introduced.?The use of LZW?dictionary algorithm,?using Java?language in the Eclipse environment?designed?for?file compression?anddecompression?algorithm using LZW?implementation procedures.?The user can according to their own?needs,?so that?the?compression?or decompressionoperation on the?file?conveniently by using the?program.?This?compression?is the essence of?digital?transformation,?contains?a large number of redundant information?in the