Patent ID: 6307488
Filing Date: 2001-10-23
Classification: G06T,H03M

Abstract:
A data compression method for compressing an input stream of data characters into an output stream of compressed codes comprisingstoring strings of data characters encountered in said input stream, said stored strings having respective codes associated therewith, a string being stored as a grouping of a predetermined number of data characters concatenated with at least one data character, said grouping of said predetermined number of data characters defining a grouped character,in a compression cycle, forming said input stream into a grouped character comprised of said predetermined number of data characters followed by at least one data character, thereby providing a formed input stream,determining the longest match between said formed input stream and said stored strings by comparing said formed input stream to said stored strings by matching said grouped character of said formed input stream with said grouped character of said stored strings and sequentially matching said at least one data character of said formed input stream with said at least one data character of said stored strings until one of the data characters of said formed input stream causes a mismatch to occur,outputting the code associated with said longest match so as to provide said output stream of compressed codes,storing an extended string comprising said longest match extended by said data character that caused said mismatch, andassigning a code corresponding to said stored extended string,said step of forming said input stream including forming a new grouped character to begin the next compression cycle, said new grouped character comprising said data character that caused said mismatch concatenated by one less than said predetermined number of the next following data characters from said input stream.