Method and apparatus for adaptive data compression
First Claim
1. A method of data compression for compressing a data record made up of a plurality of data elements each made up of a plurality of bits comprising:
- a) scanning the data record to characterize the data content of the record by at least identifying and counting the occurrence of types of data elements, and classifying data elements according to a set of predetermined groups;
b) determining within the data record the most significant of the set of predetermined groups;
c) identifying patterns of data elements in the data record in response to the step of determining including detecting and encoding repeating blocks of data elements;
d) assigning at least one of a set of predetermined compression modes in response to the identifying step; and
e) compressing the data record according to at least one of the compression modes responsive to the assigning.
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Accused Products
Abstract
The present invention relates to data compression systems and methods wherein text can be compressed by encoding repetitions of blocks of characters, or through a straight encoding scheme that converts eight-bit character values to four-bit character values by eliminating values for characters that are not valid word-starting characters or valid next-letter characters for a given preceding letter. Block compression is accomplished through the use of data structures that track the successive occurrence of valid block-repetition starting characters, and their lengths. Repeat-relative block compression is accomplished by detecting character sequences that can be expressed as the value of a previously-occurring character sequence plus or minus an offset.
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Citations
10 Claims
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1. A method of data compression for compressing a data record made up of a plurality of data elements each made up of a plurality of bits comprising:
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a) scanning the data record to characterize the data content of the record by at least identifying and counting the occurrence of types of data elements, and classifying data elements according to a set of predetermined groups; b) determining within the data record the most significant of the set of predetermined groups; c) identifying patterns of data elements in the data record in response to the step of determining including detecting and encoding repeating blocks of data elements; d) assigning at least one of a set of predetermined compression modes in response to the identifying step; and e) compressing the data record according to at least one of the compression modes responsive to the assigning. - View Dependent Claims (2, 3, 4, 5)
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6. A system for compressing a data record made up of a plurality of data elements each made up of a plurality of bits comprising:
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a) means for scanning the data record to characterize the data content of the record by at least identifying and counting the occurrence of types of data elements, and classifying data elements according to a set of predetermined groups; b) means for determining within the data record the most significant of the set of predetermined groups; c) means for identifying patterns of data elements in the data record in response to the step of determining including detecting and encoding repeating blocks of data elements; d) means for assigning at least one of a set of predetermined compression modes in response to the identifying step; and e) means for compressing the data record according to at least one of the compression modes responsive to the assigning. - View Dependent Claims (7, 8, 9, 10)
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Specification