Patent ID: 6426711
Filing Date: 2002-07-30
Classification: G06T,H03M

Abstract:
A data compression method for compressing an input stream of data characters into an output stream of compressed codes, said data characters being from an alphabet of data characters, comprisingproviding a plurality of character tables corresponding to characters of said alphabet, respectively, each said character table corresponding to a respective alphabet character, storing, in said character tables, strings of data characters encountered in said input stream, said stored strings having respective codes associated therewith, a string comprising a prefix string of at least one of said characters followed by an extension character, a particular string being stored in said character tables by storing the code associated with said particular string in the character table corresponding to the extension character of said particular string at a character table location corresponding to the code of the prefix string of said particular string, searching said input stream by comparing said input stream to said stored strings to determine the longest match therewith, said searching step including searching for a string in a character table corresponding to the extension character of the string by determining if a location exists corresponding to the code of the prefix of the string in the character table corresponding to the extension character of the string that is storing the code of the string, outputting the code associated with said longest match so as to provide said output stream of compressed codes, and inserting an extended string into said character tables, said extended string comprising said longest match extended by the next data character in said input stream following said longest match, said extended string being stored in the character table corresponding to said next data character.