Method and apparatus for modifying color reduction depending on tone
US4590515A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 13, 1983 |
| Grant date | May 20, 1986 |
| Priority date | — |
| Expiry date | May 13, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/6027
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A four color printing system wherein tone dependent color reduction is to be utilized and the color components for the chromatic printing inks yellow (Y), magenta (M) and cyan (C) are reduced and the amount of black printing ink (K) is increased so as to compensate for the reduction in the chromatic printing inks wherein a nearly total achromatic synthesis is utilized to a gray tone value which corresponds to the full tone of the black printing ink utilized. The color components of the color printing inks are then from this tone value increased from this gray tone up to the greatest image depth. So as to avoid breaks or steps in the light tone area, the color components of the chromatic printing inks are also increased in a subtonal area, particularly in the light tone area wherein reproductions can be made with or without gray tone balance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.