Fast decoding algorithms for variable-lengths codes

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Bibliographic Details
Title: Fast decoding algorithms for variable-lengths codes
Authors: Walder, Jiří, Krátký, Michal, Bača, Radim, Platoš, Jan, Snášel, Václav
Publisher Information: Elsevier
Publication Year: 2012
Collection: DSpace VŠB-TUO (Vysoká škola báňská - Technická univerzita Ostrava / Technical University of Ostrava)
Subject Terms: data compression, fast decoding algorithms, fibonacci codes, elias-delta code, elias–fibonacci code
Description: Data compression has been widely applied in many data processing areas. Compression methods use variable-length codes with the shorter codes assigned to symbols or groups of symbols that appear in the data frequently. There exist many coding algorithms, e.g. Elias-delta codes, Fibonacci codes and other variable-length codes which are often applied to encoding of numbers. Although we often do not consider time consumption of decompression as well as compression algorithms, there are cases where the decompression time is a critical issue. For example, a real-time compression of data structures, applied in the case of the physical implementation of database management systems, follows this issue. In this case, pages of a data structure are decompressed during every reading from a secondary storage into the main memory or items of a page are decompressed during every access to the page. Obviously, efficiency of a decompression algorithm is extremely important. Since fast decoding algorithms were not known until recently, variable-length codes have not been used in the data processing area. In this article, we introduce fast decoding algorithms for Elias-delta, Fibonacci of order 2 as well as Fibonacci of order 3 codes. We provide a theoretical background making these fast algorithms possible. Moreover, we introduce a new code, called the Elias–Fibonacci code, with a lower compression ratio than the Fibonacci of order 3 code for lower numbers; however, this new code provides a faster decoding time than other tested codes. Codes of Elias–Fibonacci are shorter than other compared codes for numbers longer than 26 bits. All these algorithms are suitable in the case of data processing tasks with special emphasis on the decompression time. ; Web of Science ; 183 ; 1 ; 91 ; 66
Document Type: article in journal/newspaper
File Description: 1785445 bytes; application/pdf
Language: English
Relation: Information Sciences; http://dx.doi.org/10.1016/j.ins.2011.06.019; http://hdl.handle.net/10084/89842; Není ve fondu ÚK; 000297611500005
DOI: 10.1016/j.ins.2011.06.019
Availability: http://hdl.handle.net/10084/89842
https://doi.org/10.1016/j.ins.2011.06.019
Rights: openAccess
Accession Number: edsbas.B8642D6F
Database: BASE
Description
Abstract:Data compression has been widely applied in many data processing areas. Compression methods use variable-length codes with the shorter codes assigned to symbols or groups of symbols that appear in the data frequently. There exist many coding algorithms, e.g. Elias-delta codes, Fibonacci codes and other variable-length codes which are often applied to encoding of numbers. Although we often do not consider time consumption of decompression as well as compression algorithms, there are cases where the decompression time is a critical issue. For example, a real-time compression of data structures, applied in the case of the physical implementation of database management systems, follows this issue. In this case, pages of a data structure are decompressed during every reading from a secondary storage into the main memory or items of a page are decompressed during every access to the page. Obviously, efficiency of a decompression algorithm is extremely important. Since fast decoding algorithms were not known until recently, variable-length codes have not been used in the data processing area. In this article, we introduce fast decoding algorithms for Elias-delta, Fibonacci of order 2 as well as Fibonacci of order 3 codes. We provide a theoretical background making these fast algorithms possible. Moreover, we introduce a new code, called the Elias–Fibonacci code, with a lower compression ratio than the Fibonacci of order 3 code for lower numbers; however, this new code provides a faster decoding time than other tested codes. Codes of Elias–Fibonacci are shorter than other compared codes for numbers longer than 26 bits. All these algorithms are suitable in the case of data processing tasks with special emphasis on the decompression time. ; Web of Science ; 183 ; 1 ; 91 ; 66
DOI:10.1016/j.ins.2011.06.019