Packed Lempel-Ziv-Welch Compression
Publication Date: 2004-Dec-23
The IP.com Prior Art Database
The LZW algorithm produces a series of tokens T that are integers within the range 0 to N, where N is a known variable. Traditionally the tokens are packed into a bit stream by writing B bits, where B is the smallest integer such that 2B ³ N. With additional logic, it is possible to improve the packing efficiency and save approximately a half a bit per code. The lowest significant bits (LSBs) of the token T are examined. If a one in the most significant bit (MSB) would result in a token larger than N, then this bit is extraneous, and may be omitted from the bit stream.