The Myriad Virtues of Wavelet Trees

Article history: Received 20 March 2008 Revised 17 November 2008 Available online 29 January 2009 Wavelet Trees have been introduced by Grossi et al. in SODA 2003 and have been rapidly recognized as a very flexible tool for the design of compressed full-text indexes and data compression algorithms. Although several papers have investigated the properties and usefulness of this data structure in the full-text indexing scenario, its impact on data compression has not been fully explored. In this paper we provide a throughout theoretical analysis of awide class of compression algorithmsbasedonWavelet Trees. Also,wepropose a novel framework, called Pruned Wavelet Trees, that aims for the best combination of Wavelet Treesofproperly-designedshapesandcompressors eitherbinary (like, Run-Length Encoders) or non-binary (like, Huffman and Arithmetic encoders). © 2009 Elsevier Inc. All rights reserved.