Systems and methods for illuminant estimation
US7616810B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2008 |
| Grant date | Nov 10, 2009 |
| Priority date | — |
| Expiry date | Mar 14, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/73
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Aspects of the present invention comprise systems and methods for image illuminant estimation. Some aspects relate to computing an image histogram comprising data relating the frequency of image element color values to color values found under said candidate illuminants, determining match scores for the plurality of candidate illuminants, determining a minimum match score of the match scores and determining minimum match score chromaticity coordinates. Some aspects relate to fitting a surface to the match scores wherein the surface represents illuminant parameter values other than the candidate illuminants, solving for an extremum of the surface and determining chromaticity coordinates of the extremum. Some aspects relate to selecting estimated image illuminant coordinates based on the relative location of the coordinates of one of the candidate illuminants, the coordinates of the extremum and/or the minimum match score chromaticity coordinates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.