Patent · US Expired

Method of generating an expanded color set of a low resolution color printer

US4894665A · kind A · utility

10Cited by
1References
18Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 20, 1989
Grant dateJan 16, 1990
Priority date
Expiry dateApr 20, 2009

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/52
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

In a low resolution color printer having a color set, a set of shaded colors is generated thereby expanding the color set of the printer. The method for generating the shaded colors determines if a critical line is to be printed. Then a check is made to determine if a shaded color is to be printed. If a pattern of a shaded color is to be printed, including a non-critical line, a first algorithm is used to generate a print buffer by interspersing a dark (quasi-black) colored pixel among the colored pixels, the blending effect resulting in a shaded color. If a critical line of a shaded color is to be printed, a second algorithm is utilized (to overcome a deficiency of the first algorithm) to insure an interspersing of the dark pixels with colored pixels. Otherwise, the pattern is printed in the designated color.

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