Data sequence compression
AssigneeHewlett-Packard Development Company, L.P.
InventorsErik Ordentlich, Marcelo Weinberger
Life of this patent
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Abstract
In a method of compressing a data sequence, the data sequence is parsed into data segments, where at least one of the data segments includes a match. In addition, the match is compressed using at least one context model that depends upon one or more coded data symbols that are available to a decoder. An encoder includes a coding unit configured to code at least one of a match offset and a match length of a data segment using one or more context models that depend on previously decodeable data symbols. A computer readable storage medium having a computer program for implementing the method of compressing the data sequence.
Claims17
A method of compressing a data sequence, said method comprising:
- parsing the data sequence into data segments, wherein at least one of the data segments includes a match;
- determining a match offset and a match length of the match;
- determining a modified match offset and modified match length by respectively subtracting minimum values from the match offset and the match length;
- determining most significant bits and least significant bits of at least one of the modified match offset and the modified match length;
- and
- compressing at least one of the match offset and the match length by compressing the least significant bits of at least one of the modified match offset and the modified match length using at least one context model that depends upon one or more coded data symbols that are available to a decoder.
An encoder comprising:
- a coding unit configured to code at least one of a modified match offset and a modified match length of a data segment using one or more context models that depend on previously decodeable data symbols,
- wherein the modified match offset comprises most significant bits and least significant bits and the modified match length comprises most significant bits and least significant bits, and
- wherein the coding unit is further configured to code at least one of the modified match offset least significant bits and the modified match length least significant bits using the one or more context models.
A computer readable storage medium on which is embedded one or more computer programs, said one or more computer programs implementing a method for compressing a data sequence, said one or more computer programs comprising a set of instructions for:
- parsing the data sequence into data segments, wherein at least one of the data segments includes a match;
- determining a match offset and a match length of the match;
- determining a modified match offset and modified match length by respectively subtracting minimum values from the match offset and the match length;
- determining most significant bits and least significant bits of at least one of the modified match offset and the modified match length;
- and
- compressing at least one of the match offset and the match length using by compressing the least significant bits of at least one of the modified match offset and the modified match length using at least one context model that depends upon one or more coded data symbols that are available to a decoder.
A method of decompressing a coded data sequence, said method comprising:
- receiving a coded data segment, wherein the coded data segment comprises at least one of a modified match offset and a modified match length of the data segment wherein the modified match offset and the modified match length have respective most significant bits and least significant bits, and wherein the least significant bits of at least one of the modified match offset and the modified match length has been coded using one or more context models that depends upon one or more coded data symbols that are available to a decoder;
- and
- decompressing the received coded data segment.
Dependencies are inferred from the claim text.