Method and apparatus for correction of color shifts due to illuminant changes
US5771311A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 27, 1995 |
| Grant date | Jun 23, 1998 |
| Priority date | — |
| Expiry date | Dec 27, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/6086
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Color separation values such as CMYK values from an input device are transformed into characteristic parameter values by a first transforming device having a neural network which has undergone learning in advance in such a manner as to output characteristic parameter values obtained by multivariate analysis of spectral distributions which correspond to the color separation values and are illuminant-independent. These characteristic parameter values are subjected to a linear transformation by a second transforming device, the linear transformation having a constraint that calorimetric values under a specified illuminant are to be equal or another similar constraint, by using mean vectors and eigenvectors (principal component vectors) of predetermined spectral reflectances stored in a storage device. The transformed characteristic parameter values are transformed into color separation values of a target color reproduction device by a third transforming device having a neural network which has undergone learning in advance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.