Patent · US Expired

Digital copying apparatus capable of forming a superior quality image with a reduced amount of memory

US5920646A · kind A · utility

29Cited by
3References
16Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 4, 1997
Grant dateJul 6, 1999
Priority date
Expiry dateMar 4, 2017

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/4092
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A digital copying apparatus provides high quality copy images suitable for an original document image while reducing a necessary capacity of a memory for storing image data. An image signal read by an image reading unit is binarized by a binary gradation processing unit in a gradation processing unit and is stored in a memory unit. Then, binary image data read from the memory unit is applied to a multi-value processing unit, wherein a pattern recognition unit determines whether or not the binary image data includes a pixel which requires a jagged line correction, and a halftone detector detects a halftone region in the binary image data. A determination unit and a selector select jagged line correction data output from a pattern memory and multi-valued image data converted from the binary image data by a multi-value filter. The selected data is output to an image forming unit.

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