Image analysis – Image compression or coding – Lossless compression
Reexamination Certificate
2005-04-05
2005-04-05
Chen, Wenpeng (Department: 2624)
Image analysis
Image compression or coding
Lossless compression
C382S229000, C341S051000
Reexamination Certificate
active
06876774
ABSTRACT:
The present invention provides a data compression method in which a plurality of consecutive characters of a data string to be compressed are set as a character string to be searched for. Bits of a bit string representing the set character string are allocated to at least two codewords. Thus, first and second searching codewords are generated. These first and second codewords are used as array addresses. First and second array tables are prepared, in which information on the past occurrence positions of the set character string is previously entered as the contents thereof. When the first and second codewords are generated from the character string to be compressed, the first and second array tables are looked up by using these codewords as the addresses of the arrays. When results of looking up these tables match with each other, it is found that the set character string occurred in the past. Thus, information on the past occurrence position information of the set character string is obtained according to the obtained array content. Then, this information is encoded, so that data compression is performed. Thus, the amount of memory needed for the tables is significantly reduced, while information on the past occurrence position of the set character string is obtained without reducing a searching speed.
REFERENCES:
patent: 4071745 (1978-01-01), Hall
patent: 5016009 (1991-05-01), Whitling et al.
patent: 5136289 (1992-08-01), Yoshida et al.
patent: 5155484 (1992-10-01), Cahmbers, IV
patent: 5254990 (1993-10-01), Yoshida et al.
patent: 5389922 (1995-02-01), Seroussi et al.
patent: 5533051 (1996-07-01), James
patent: 5635932 (1997-06-01), Shinagawa et al.
patent: 5951623 (1999-09-01), Reynar et al.
patent: 05113869 (1993-05-01), None
“Multiple-Dictionary Compression Using Partial Matching,” Hoang, D.T. et al., Proceeding of Data Compression Conference, 1995, pp. 272-281.*
“Highly Efficient Universal Coding with Classifying to Subdiictionaries for Text Compression,” Kakano, Y. et al., Proceeding of Data Compression Conference, 1994, pp. 234-243.*
Williams, Ross N., “An xtremely Fas ZIV-Lampel Data compression Algorithm”, pp. 362-371, 1991.
Satoh Noriko
Yoshida Shigeru
Chen Wenpeng
Fujitsu Limited
Staas & Halsey , LLP
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