Improving Static Compression Schemes by Alphabet Extension
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The performance of data compression on a large static text may be improved if certain variable-length strings are included in the character set for which a code is generated. A new method for extending the alphabet is presented, based on a reduction to a graph-theoretic problem. A related optimization problem is shown to be NP-complete, a fast heuristic is suggested, and experimental results are presented.
KeywordsPosition Tree Greedy Heuristic Black Vertex Arithmetic Code Fast Heuristic
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