LZRW1

The LZRW1 algorithm was the first of a series of high-speed "LZRW" text compression algorithms created from 1990 to 1992. The root name "LZRW" stands for "Lempel-Ziv Ross Williams". I couldn't use the name "LZW", as that was already taken by Welch, so I used "LZRW" and numbered the algorithms I created.

The LZRW1 algorithm is defined precisely and clearly in the following paper which includes complete, but rather densely laid out C source code:

Williams, R.N., "An Extremely Fast Ziv-Lempel Data Compression Algorithm", Data Compression Conference 1991 (DCC'91),  8-11 April , 1991, Snowbird, Utah, pp.362-371, IEEE reference code: TH0373-1/91/0000/0362/$01.00.

The algorithm falls in the LZ77 (LZ1) class. For more details, see the paper which also appears below as old_lzrw1.tex (but which doesn't contain the diagrams).

On 25 June 1991, a descendent algorithm of LZRW1 called LZRW1-A was released.

Original Versions

• ftp://ftp.ross.net/compression/original/old_lzrw1.tex
• ftp://ftp.ross.net/compression/original/old_lzrw1.c
• ftp://ftp.ross.net/compression/original/old_lzrw1.68000

New Version