Patent · US Expired

Method and an apparatus for coding/decoding telewriting signals

US4597101A · kind A · utility

26Cited by
7References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 28, 1983
Grant dateJun 24, 1986
Priority date
Expiry dateJun 28, 2003

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06V30/347
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A difference vector indicating movement of a pen between two adjacent sampled points is divided into macro movement and micro movement components. The macro and micro components are coded independently of each other so as to provide effective coding. In the case of coding the difference vector, the magnitude of the difference vector is coded in accordance with the types of zones (zone number k) and relative pel address within the zone. In order to improve the coding efficiency, a zone number difference is used instead of the zone number. Furthermore, the direction of the difference vector is expressed by a quadrant which includes this difference vector. In order to further improve the coding efficiency, a quadrant number difference is used instead of the quadrant number.

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