Patent · US Expired

Device for coding a picture signal by compression

US5051840A · kind A · utility

90Cited by
4References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 12, 1989
Grant dateSep 24, 1991
Priority date
Expiry dateDec 12, 2009

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N19/91
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A picture signal compression coding device divides picture data into a plurality blocks and subjects the individual blocks of picture data to an orthogonal transform, a normalization, and a coding. The amounts of data to be allocated to the individual blocks are determined on the basis of the ratios of the activities of the individual blocks to a sum of the block-by-block activities, whereby the output of the individual blocks of coded data is restricted. The amount of coded data is allocated in matching relation to the frequency components of the individual blocks, so that more data are distributed to those blocks in which high frequency components are predominant. Further, the number of bits to be assigned to the entire picture is maintained constant.

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