Method and apparatus using a conversion table based on pre-printed color charts for determining half-tone dot percents required to reproduce the color of a color specimen
US4717954A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 1984 |
| Grant date | Jan 5, 1988 |
| Priority date | — |
| Expiry date | May 8, 2004 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41F33/0027
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for obtaining an accurate half-tone dot percent of each color separation where a color designated by a color specimen is to be reproduced by printing of ink of the colors, for example, yellow, magenta, cyan and black. A variety of color charts printed using predetermined combinations of half-tone dot percents are optically measured to obtain color information of the colors printed on the color charts. The obtained color information values together with the corresponding predetermined combinations of half-tone dot percents therefor are then utilized to prepare a conversion table of color information and corresponding half-tone dot percents for reproducing each of the colors printed on the color charts. A color specimen is then optically measured to detect color information of a color to be reproduced. The color information obtained from the color specimen is then successively compared with the color information of the conversion table, and the color information of the conversion table is selected which most closely corresponds to the color information obtained from the color specimen. The combination of half-tone dot percents corresponding to the selected colo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.