Coded data generation or conversion – Digital code to digital code converters – To or from variable length codes
Patent
1989-01-13
1991-05-14
Pellinen, A. D.
Coded data generation or conversion
Digital code to digital code converters
To or from variable length codes
341 95, 341106, 375112, 370102, H03M 740, H03L 700
Patent
active
050160095
ABSTRACT:
An apparatus and method for converting an input data character stream into a variable length encoded data stream in a data compression system. The data compression system includes a history array means. The history array means has a plurality of entries and each entry of the history array means is for storing a portion of the input data stream. The method for converting the input data character stream includes the following steps. Performing a search in a history array means for the longest data string which matches the input data string. If the matching data string is found within the history buffer means, the next step includes encoding the longest matching data string found by appending to the encoded data stream a tag indicating the longest matching data string was found and a string substitution code. If the matching data string is not found within the history array means, the next step includes encoding the first character of the input data string by appending to the encoded data stream a raw data tag indicating that no matching data string was found and the first character of the input data string.
REFERENCES:
patent: 3976844 (1976-08-01), Betz
patent: 4021782 (1977-05-01), Hoerning
patent: 4054951 (1977-10-01), Jackson et al.
patent: 4412306 (1983-10-01), Moll
patent: 4464650 (1984-08-01), Eastman et al.
patent: 4491934 (1985-01-01), Heinz
patent: 4558302 (1985-12-01), Welch
patent: 4612532 (1986-09-01), Bacon et al.
patent: 4701745 (1987-10-01), Waterworth
patent: 4814746 (1989-03-01), Miller et al.
patent: 4876541 (1989-10-01), Storer
J. Cleary et al., "Data Compression Using Adaptive Coding and Partial String Matching", IEEE Transactions on Communications, 32:396-403 (1984).
M. Wells, "File Compression Using Variable Length Encodings," The Computer Journal, 15:308-313 (1972).
George Glen A.
Ivey Glen E.
Whiting Douglas L.
Logan Sharon D.
Pellinen A. D.
Stac, Inc.
LandOfFree
Data compression apparatus and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Data compression apparatus and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Data compression apparatus and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1651575