History of Data Compression Algorithms By Michael Riha

Questions to Answer How have compression algorithms evolved over time? What methods do they use to compress and how are they interrelated? What real-world applications do they have, and how have they changed? What priority do they place on speed vs. compression ratio? What effect have software patents had on the development of compression algorithms?

Sliding Window Algorithms LZ77(Lempel-Ziv #1)1977 LZSS(Lempel-Ziv-Storer-Szymanski)1982 LZRW(Lempel-Ziv Ross Williams)1991 LZJB(Lempel-Ziv Jeff Bonwick)1998 LZR (Lempel-Ziv-Renau)??? DEFLATE (ZIP, PNG, gzip, etc.)1993 DEFLATE64 (Proprietary)1999 LZS(Lempel-Ziv-Stac)1994 LZX(Used in Microsoft.CAB)1995 LZP(Usually a preprocessor)1995 LZO(Lempel-Ziv-Oberhumer)1996 LZMA (Lempel-Ziv-Markov Chain)1998

Dictionary Algorithms LZ78(Lempel-Ziv #2)1978 LZW (Lempel-Ziv-Welch)1984 LZMW(Syllable-based LZW)1985 LZAP1988 LZWL2006 bzip2(Algorithm Amalgam)1996 PAQ*(Context Mixing)2002 PAQ8O(Faster, higher CR)2007 Many others Statistical LZ ROLZ (Reduced Offset LZ)

Methods Dictionary Compression (ubiquitous) Prediction by Partial Matching (PPM, used by 7-Zip and RAR) Context Mixing (Combines multiple statistical models) Entropy Encoding Huffman Coding (Used in DEFLATE, bzip2, SSH, etc.) Adaptive Huffman Coding (Dynamic scope) Shannon-Fano Coding (Suboptimal compared to Huffman) Arithmetic & Range Encoding Rice & Golomb Coding (FLAC uses Rice, not used general purpose) Universal Coding (Slower than Huffman, uncommon) Run-Length Encoding (AAAAAAABBBBA => 7A4BA) Burrows-Wheeler Transform (Preprocessor for Run-length Encoding)

Materials Google Scholar / SJSU Library Databases Regular Google Wikipedia links to many detailed descriptions/specifications/implementations of algorithms A few sources, mainly technical papers: ompression ompression Have not contacted any project advisors, not sure who would have expertise