说明：  熵编码(entropy encoding)是一类利用数据的统计信息进行压缩的无语义数据流之无损编码。本章先介绍熵的基本概念，然后介绍香农-范诺(Shannon-Fano)编码、哈夫曼(Huffman)编码、算术编码(arithmetic coding)、行程编码(RLE)和LZW编码等常用的熵编码方法。
(Entropy coding (entropy encoding) is a kind of the compressed by using the data statistics of the semantic data flow lossless coding.This chapter first introduce the basic concept of entropy, then introduce Shannon- he (Shannon- Fano) coding, Huffman (Huffman coding, arithmetic coding, arithmetic coding), run length encoding (RLE) and entropy coding methods such as LZW encoding.)