Patent · US Expired

Normalizing correlator for video processing

US5133022A · kind A · utility

59Cited by
11References
3Claims
0Family size

Assignee

Inventor

Key dates

Filing dateFeb 6, 1991
Grant dateJul 21, 1992
Priority date
Expiry dateFeb 6, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06V2201/00
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A video image processor for generating an enhanced image of data based upon input gray scale picture element values of image data of a document background and printed information contained thereon generates a histogram of the gray scale picture element values for each tile of image data for an area of the document representing the frequency of occurrence of picture elements of a particular gray scale value. A correlator processes each histogram to determine a back reference level and a white reference level for each tile. Normalization factors are calculated based upon the black reference level and the white reference level. The input gray scale picture element values for each tile of the image data associated with the normalization factors of each tile are normalized based upon the normalization factors for each tile and correlated to generate a normalized and correlated representation of the image data.

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