Patent · US Expired

Image processing apparatus especially suitable for producing smooth-edged output multi-level tone data having fewer levels than input multi-level tone data

US5339171A · kind A · utility

34Cited by
8References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 4, 1992
Grant dateAug 16, 1994
Priority date
Expiry dateJun 4, 2012

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/4057
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An image processing apparatus includes a scanner for inputting image data indicative of an image with a multilevel tone, a multilevel data part for generating multilevel tone data from the input image data through a prescribed error diffusion process, the multilevel data part outputting image data having pixels to which the multilevel tone data is assigned, a storage part for temporarily storing a value of one of two successive pixels included in the image data, and a two-pixel processing part for converting the value of the one pixel stored in the storage part into a first value, and for generating second values of the two successive pixels using the first value of the one pixel, so that output image data is output to a printer, each pixel of the output image data being described by the second values of the two successive pixels.

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