Patent · US Expired

Adaptive transform coding using variable block size

US5241395A · kind A · utility

192Cited by
6References
16Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 23, 1992
Grant dateAug 31, 1993
Priority date
Expiry dateMar 23, 2012

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N19/96
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An adaptive transform coding algorithm for a still image utilizes a quadtree based variable block size discrete cosine transform to achieve a better tradeoff between bit rate and image quality. The choice of appropriate block size is made according to a mean based decision rule which can discriminate various image contents for better visual quality.

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