Text-Based Data Compression Algorithms: Huffman, LZW, Arithmetic, and RLE

This document outlines various text-based data compression algorithms, including Huffman coding, Adaptive Huffman coding, LZW, Arithmetic coding, and Run Length Encoding (RLE). It also mentions where to find related MATLAB code examples.

For a general understanding of lossless vs. lossy data compression and their respective types, consider researching those topics before diving into the specific algorithms.

Huffman Coding (MATLAB Code)

• Input sequence to Huffman encoder: ABCAAAACCCCAAAAACCCCAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
• Output sequence from Huffman encoder: ABCDABCBEB
• Input sequence to Huffman decoder: ABCDABCBEB
• Output sequence from Huffman decoder: ABCAAAACCCCAAAAACCCCAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

Run Length Encoding (RLE) (MATLAB Code)

• Input to RLE encoder: AAAABBCDDDDEEEZXXX
• Output from RLE encoder: ABCDEZX
• Input to RLE decoder: ABCDEZX
• Output from RLE decoder: AAAABBCDDDDEEEZXXX

Dictionary-Based Data Compression (LZW Algorithm) (MATLAB Code)

• Input in LZW compression code: ‘/WED/WE/WEE/WEB/WET’

The output from the LZW encoder is the ASCII value generated based on entries in the dictionary. If an entry is new, an ASCII value is assigned, and the entry is added to the dictionary.

Example dictionary generation:

/W WE ED D/ /WE E/ /WEE E/W WEB B/ /WET

Arithmetic Coding (MATLAB Code)

• Input sequence to Arithmetic coding: ABCAAAACCCCAAAAACCCCAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
• Output from Arithmetic encoder: ABCDABCBEB
• Input to Arithmetic decoder: ABCDABCBEB
• Output from Arithmetic decoder: ABCAAAACCCCAAAAACCCCAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

Download Source Code

Download source code examples from these links:

• https://www.sourcecodeonline.com/
• https://www.data-compression.com/download.shtml