The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 21, 2000
Filed:
May. 29, 1998
Simon M Law, Torrance, CA (US);
Xerox Corporation, Stamford, CT (US);
Abstract
Many compression algorithms require the compressor to generate trees (tables) for encoding purposes. To generate the optimum tree for a set of Huffman symbols either takes too much time or requires too much hardware. This invention proposes to separate the symbols into groups according to the symbol's occurring frequency. With these groups of symbols available, subsequent code length assignment of these groups can be done without a complete sorting of all the symbols and their parents. During code length assignment, some relocation of individual symbols from one group to another can also be performed to optimize the Huffman table. In most of the cases this technique can achieve a compression ratio within 5% of the optimum Huffman table, while requiring less hardware or software overhead.