Lempel-Ziv compression scheme with enhanced adapation
US5243341A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1992 |
| Grant date | Sep 7, 1993 |
| Priority date | — |
| Expiry date | Jun 1, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T9/005
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A class of lossless data compression algorithms use a memory-based dictionary of finite size to facilitate the compression and decompression of data. When the current dictionary (CD) fills up with encoded character strings, it is reset thereby losing the compression information previously contained in the dictionary. To reduce the loss in data compression caused by dictionary resets, a second, standby dictionary (SD) is used to simultaneously store a subset of the encoded data entries stored in the first dictionary. The data entries in the second dictionary represent the data entries of the first dictionary that compress the greatest amount of input data. When the first dictionary is ready to be reset, the first dictionary is replaced with the second dictionary, maintaining high data compression and freeing up memory space for new encoded data strings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.