Patent · US Expired

High speed data compression and decompression apparatus and method

US4558302A · kind A · utility

490Cited by
1References
181Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 20, 1983
Grant dateDec 10, 1985
Priority date
Expiry dateJun 20, 2003

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03M7/3088
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A data compressor compresses an input stream of data character signals by storing in a string table strings of data character signals encountered in the input stream. The compressor searches the input stream to determine the longest match to a stored string. Each stored string comprises a prefix string and an extension character where the extension character is the last character in the string and the prefix string comprises all but the extension character. Each string has a code signal associated therewith and a string is stored in the string table by, at least implicitly, storing the code signal for the string, the code signal for the string prefix and the extension character. When the longest match between the input data character stream and the stored strings is determined, the code signal for the longest match is transmitted as the compressed code signal for the encountered string of characters and an extension string is stored in the string table. The prefix of the extended string is the longest match and the extension character of the extended string is the next input data character signal following the longest match. Searching through the string table and entering extended …

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.