Color dependent luminance processing
US6731797B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 14, 2001 |
| Grant date | May 4, 2004 |
| Priority date | — |
| Expiry date | Oct 16, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/62
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and structure for developing a photographic image from a camera, filtering the image, and developing the image. Filtering of an image entails separating the image into a luminance channel and chrominance channels, alternating the luminance channel by saturation and hue to produce the altered luminance channel and recombining the chrominance channels and the altered luminance channel. The hue controls the color of filtering and the saturation controls the strength of the filtering. Prior to separating and converting the linear exposure is converted to a logarithmic space. This conversion of linear exposure to logarithmic space allows the luminance's channel to be altered independently from the chrominance channels. The alteration creates a filtered RGB to YCrCb matrix and applying the matrix to the logarithmic space produces a filtered logarithmic space. The invention recombines the YCrCb to RGB matrix to the filtered logarithmic space.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.