Patent · US Expired

Image processing apparatus

US5153925A · kind A · utility

78Cited by
10References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 27, 1990
Grant dateOct 6, 1992
Priority date
Expiry dateApr 27, 2010

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/4053
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An image processing apparatus comprises: first binarizing means for binarizing input image data by an average value based on the binarized data of pixels near an objective pixel which has already been binarized; second binarizing means for binarizing the input image data by a predetermined threshold vlaue; and selecting means for selecting either one of the first and second binarizing means in accordance with whether the input image data indicates an edge portion or not, whereby by selecting either a binarizing process by the average density preservation method or a binarizing process by a fixed threshold value in accordance with the presence or absence of an edge of input data, an image of a high grade can be reproduced for either a half tone image or a character image.

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