Light source estimating device, light source estimating method, and imaging device and image processing method
US7436997B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 2003 |
| Grant date | Oct 14, 2008 |
| Priority date | — |
| Expiry date | May 19, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/88
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A light source estimation method of this invention estimates from the sensor response the color characteristics of an unknown light source of an image-pickup scene, in order to improve white balance adjustment and other aspects of the quality of color reproduction; a projection conversion portion 6 projects sensor response values 5 into an image distribution 9 in an evaluation space not dependent on the image-pickup light source 2 using parameters obtained by operations which can be calorimetrically approximated from spectral sensitivity characteristics of image-pickup unit 4, which are known, and from spectral characteristics of an assumed test light source 1; an evaluation portion 10 evaluates the correctness of a plurality of the test light sources 1 based on the distribution state of sample values of the projected scene; and accordingly, the correct image-pickup light source 2 is estimated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.