Patent ID: 6518895
Filing Date: 2003-02-11
Classification: H03M

Abstract:
A method of compressing a dataset that includes a number N of distinct symbols, all of the symbols having a common length, comprising the steps of:(a) ranking the symbols by frequency, thereby assigning to each symbol a respective rank i; (b) selecting a number Q of classes; (c) selecting Q distinct class codes cj indexed by an index j such that 1&lE;j&lE;Q; and (d) for each symbol: if said rank i of said each symbol is such that 2qâˆ’1&lE;i&lE;2qâˆ’1 for an integer q&lE;Q: (i) assigning said class code cq to said each symbol, thereby classifying said each symbol according to a successive-powers-of-two class size scheme, (ii) assigning a respective symbol code to said each symbol, and (iii) replacing at least one occurrence of said each symbol in the dataset with a concatenation of cq and said symbol code of said each symbol, thereby providing a compressed dataset.