Search And Retrieval Of Compressed Text

In recent times, we have witnessed an unprecedented growth of textual information via the Internet, digital libraries and archival text in many applications. To be able to store, manage, organize and transport the data efficiently, text compression is necessary. We also need efficient search engines to speedily find the information from this huge mass of data, especially when it is compressed. In this chapter, we present a review of text compression algorithms, with particular emphasis on the LZ family algorithms, and present our current research on the family of Star compression algorithms. We discuss ways to search the information from its compressed format and introduce some recent work on compressed domain pattern matching, with a focus on a new two-pass compression algorithm based on LZW algorithm. We present the architecture of a compressed domain search and retrieval system for archival information and indicate its suitability for implementation in a parallel and distributed environment using random access property of the two-pass LZW algorithm. © 2005 Elsevier Inc. All rights reserved