Patent · US Expired

Shading correction device

US4524388A · kind A · utility

19Cited by
5References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 6, 1982
Grant dateJun 18, 1985
Priority date
Expiry dateAug 6, 2002

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/401
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A shading correction device wherein in advance to the reading of the document image, shading correction coefficients are obtained from optic information from uniform reflecting surface and stored in a memory element such as RAM, and correcting the picture signal in accordance with the content of the memory element when the document is read.

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