Patent · US Expired

Digital copier with document image region decision device

US4707745A · kind A · utility

36Cited by
3References
48Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 20, 1985
Grant dateNov 17, 1987
Priority date
Expiry dateDec 20, 2005

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/40062
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A digital copier for reproducing images carried in a document by converting them to an electrical binary or recording/non-recording signal and recording the binary signal. The copier includes a halftone image processor unit for generating a binary signal associated with a halftone image included in the scanned document images, and a binarizer unit for generating a binary signal associated with a two-level image included in the document images. The copier also includes an image region decision unit for determining to which one of a halftone image region and a two-level image region a pixel of a document image which is to be read belongs. The decision is made using binary data which is produced by processing the scanned image data with respect to a threshold level different from a threshold level adapted for simple binarization. Edges of the decided halftone image are processed in an optimum manner.

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