Color image processing method and apparatus capable of adjusting the UCR ratio
US5502579A · kind A · utility
29Cited by
7References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 20, 1993 |
| Grant date | Mar 26, 1996 |
| Priority date | — |
| Expiry date | Oct 20, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/6022
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A lightness/chromaticity separation device converts three input color signals to {L*, a*, b*} signals. A chroma determination device determines a chroma signal C* based on the {a*, b*} signals. An UCR ratio calculation device calculates an UCR ratio .alpha. according to a C*-.alpha. function that is adjustable by changing parameters. A nonlinear conversion circuit determines output color signals of four colors including black based on the {L*, a*, b*} signals and the UCR ratio. The nonlinear conversion circuit includes a network-type combination of a plurality of analog nonlinear operation units.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.