Color modification utilizing two coefficients
US5278640A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 1990 |
| Grant date | Jan 11, 1994 |
| Priority date | — |
| Expiry date | Sep 24, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/6019
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A pictorial image comprising pixels represented by a combination of density values in respect to first color components (R, G, B) is transformed to a pictorial image comprising pixels represented by combination of density values in respect to second color components (C, M, Y). In accordance with the first color modification method, an operation expressed as Q=.alpha.P+.beta. is implemented to an original density value P using two correction coefficients .alpha. and .beta. determined in advance to determine a density value Q after transformation. In addition, in accordance with the second color modification method, density values after transformation are determined by the calculation of the k-th degree masking equation using the k-th degree masking coefficients. At this time, a color cube is defined with respect to the first color components. The color cube thus defined is devided into an n number of blocks. The k-th degree masking coefficients are defined every respective blocks. Then, calculation of the k-th degree masking equation is performed using the k-th degree masking coefficients defined with respect to blocks involving points indicative of original density values within th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.