23.08.2010
The Gray code
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Annotation: Description of the Gray code and alghorithms above it, from initial task to calculate gray-encoded numerics sum.
Keywords: Gray code; |
22.09.2011
Constructor of PPM codecs
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Annotation: The paper proposes the implementation of a family of PPM compressors as a customizable set of C++ templates. It's possible to construct PPM codecs using these templates that can support context model orders from the 1st to the 10th inclusive with or without memory restriction. The various known methods of escape code calculation are analyzed in this paper including a new original method proposed by the author. This family of PPM compressors supports the different methods of compression improvement such as LOE, symbols exclusion, extra weighting during initialization and others. The possibility to include any other additional methods to improve the compression is also described.
Keywords: lossless compression; codec; Prediction by Partial Matching; PPM; escape code; PPMtc; finite context modeling;C++; |
29.12.2011
Partial PPM codecs
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Annotation: This paper considers the PPM codecs, which have omissions in the context orders. Since the context model of these codecs contains gaps, they can be named as "partial", as opposed to "full" PPM codecs, which have all the context orders up to a fixed maximum order. The article compares these two types of codecs and is trying to answer the questions: is it possible to improve compression, reduce memory usage and speed up compression/decompression processes using partial PPM codecs.
Keywords: lossless compression; codec; Prediction by Partial Matching; PPM; PPMtc; C++; |
