Patent · US Expired

Compressing/decompressing bitmap by performing exclusive- or operation setting differential encoding of first and previous row therewith outputting run-length encoding of row

US6304928A · kind A · utility

91Cited by
28References
34Claims
0Family size

Assignees

Inventors

Key dates

Filing dateJul 1, 1998
Grant dateOct 16, 2001
Priority date
Expiry dateJul 1, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06T9/005
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A method and system for compressing bitmap data in a system for sharing an application running on a host computer with a remote computer, wherein the shared application's screen output is simultaneously displayed on both computers. Simultaneous display of screen output is achieved by efficiently transmitting display data between the host computer and the remote computer. When a font used by the host computer for displaying text is not available on the remote computer, the host computer sends a bitmap representation of the text for display, rather than the text itself. Bitmap representations are cached by the remote computer, so that the same bitmap representation need not be repeatedly transmitted from the host computer to the remote computer. Bitmap representations are compressed by the host computer prior to transmission, transmitted, then decompressed by the remote computer.

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