License
When quoting this document, please refer to the following
DOI: 10.4230/LIPIcs.STACS.2008.1332
URN: urn:nbn:de:0030-drops-13327
URL: http://drops.dagstuhl.de/opus/volltexte/2008/1332/
Go to the corresponding Portal


Albert, Pilar ; Mayordomo, Elvira ; Moser, Philip ; Perifel, Sylvain

Pushdown Compression

pdf-format:
Document 1.pdf (155 KB)


Abstract

The pressing need for efficient compression schemes for XML documents has recently been focused on stack computation (Hariharan and Shankar 2006, League and Eng 2007), and in particular calls for a formulation of information-lossless stack or pushdown compressors that allows a formal analysis of their performance and a more ambitious use of the stack in XML compression, where so far it is mainly connected to parsing mechanisms. In this paper we introduce the model of pushdown compressor, based on pushdown transducers that compute a single injective function while keeping the widest generality regarding stack computation. The celebrated Lempel-Ziv algorithm LZ78 was introduced as a general purpose compression algorithm that outperforms finite-state compressors on all sequences. We compare the performance of the Lempel-Ziv algorithm with that of the pushdown compressors, or compression algorithms that can be implemented with a pushdown transducer. This comparison is made without any a priori assumption on the data's source and considering the asymptotic compression ratio for infinite sequences. We prove that Lempel-Ziv is incomparable with pushdown compressors.

BibTeX - Entry

@InProceedings{albert_et_al:LIPIcs:2008:1332,
  author =	{Pilar Albert and Elvira Mayordomo and Philip Moser and Sylvain Perifel},
  title =	{{Pushdown Compression}},
  booktitle =	{25th International Symposium on Theoretical Aspects of Computer Science},
  pages =	{39--48},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-939897-06-4},
  ISSN =	{1868-8969},
  year =	{2008},
  volume =	{1},
  editor =	{Susanne Albers and Pascal Weil},
  publisher =	{Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{http://drops.dagstuhl.de/opus/volltexte/2008/1332},
  URN =		{urn:nbn:de:0030-drops-13327},
  doi =		{http://dx.doi.org/10.4230/LIPIcs.STACS.2008.1332},
  annote =	{Keywords: Finite-state compression, Lempel-Ziv algorithm, pumping-lemma, pushdown compression, XML document}
}

Keywords: Finite-state compression, Lempel-Ziv algorithm, pumping-lemma, pushdown compression, XML document
Seminar: 25th International Symposium on Theoretical Aspects of Computer Science
Issue Date: 2008
Date of publication: 06.02.2008


DROPS-Home | Fulltext Search | Imprint Published by LZI