6533b7d7fe1ef96bd1269094

RESEARCH PRODUCT

Block Sorting-Based Transformations on Words: Beyond the Magic BWT

Giovanni ManziniGiovanna RosoneAntonio RestivoRaffaele GiancarloMarinella Sciortino

subject

0301 basic medicineSettore INF/01 - InformaticaComputer scienceData_CODINGANDINFORMATIONTHEORY0102 computer and information sciencesBlock sortingData structureLexicographical order01 natural sciencesUpper and lower bounds03 medical and health sciencesCombinatorics on words030104 developmental biology010201 computation theory & mathematicsArithmeticCompressed Data Structures Block Sorting Combinatorics on Words AlgorithmsData compression

description

The Burrows-Wheeler Transform (BWT) is a word transformation introduced in 1994 for Data Compression and later results have contributed to make it a fundamental tool for the design of self-indexing compressed data structures. The Alternating Burrows-Wheeler Transform (ABWT) is a more recent transformation, studied in the context of Combinatorics on Words, that works in a similar way, using an alternating lexicographical order instead of the usual one. In this paper we study a more general class of block sorting-based transformations. The transformations in this new class prove to be interesting combinatorial tools that offer new research perspectives. In particular, we show that all the transformations in this class can be used as booster for memoryless compressors and we provide an upper bound on the number of equal-letter runs in their output. Moreover, we introduce the notion of rank-invertibility, a property related to the implementation of an efficient inversion procedure. We show that the BWT and the Alternating BWT are the only rank-invertible transformations in the class we have defined.

yearjournalcountryeditionlanguage
2018-01-01
https://doi.org/10.1007/978-3-319-98654-8_1