Patent · US Expired

Image processing apparatus carrying out multi-value error diffusion process

US6501566B1 · kind B1 · utility

13Cited by
12References
24Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 31, 1998
Grant dateDec 31, 2002
Priority date
Expiry dateMar 31, 2018

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/40087
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An image processing apparatus that can carry out an error diffusion process without degrading the quality of image data generates a density histogram according to pixels included in the input image data. Reference densities S1 and S2 are calculated from pixels having a certain density in a set range. Threshold values T1-T3 are calculated according to the obtained reference densities S1 and S2.

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