这个文档是我大学时候多媒体的一个实验作业，里面要求实现LZW压缩方法。大家可以在文档中自行查阅。(This document is an experimental operation of multimedia in my university. It requires four simple compression methods, namely, Huffman, adaptive Huffman, LZW and arithmetic coding. Because of the need of practice at that time, the four methods of compression are slightly different in the way of implementation. You can look up in the document.)