Reproduction of colored images including overprinting for reproduction of bright colors
US4774567A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 1987 |
| Grant date | Sep 27, 1988 |
| Priority date | — |
| Expiry date | Sep 16, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/54
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In color printing it is customary to print images in a combination cyan, magneta, and yellow printing inks. However, it is sometimes required in the printing of the final image, to include an ink of a special color, for example a brown ink, which cannot be reproduced by combining cyan, magenta and yellow inks. The present invention is concerned with the preparation of a special color printer for a special printing ink. According to the invention sets of values (C.sub.ROP, M.sub.ROP, Y.sub.ROP, K.sub.ROP) defining the characteristic elements of curves for cyan, magenta, yellow, and black, which curves together correspond to a range of values for the overprinted colored separation, are stored. For each picture element, a combination of color component values for cyan, magenta, yellow and black (C,M,Y,K) are derived and compared with different sets of values (C.sub.ROP, M.sub.ROP, Y.sub.ROP, K.sub.ROP) derived from the stored curve elements, each set corresponding to a different value of the overprinted special color separation (R.sub.OP). A value is selected for the desired special color separation for which each of the stored values of the related set (C.sub.ROP, M.sub.ROP, Y.sub.RO…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.