Method and apparatus for adjusting the contrast of an image
US7738698B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 26, 2006 |
| Grant date | Jun 15, 2010 |
| Priority date | — |
| Expiry date | Jul 8, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/147
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for adjusting the contrast of an image, in which each pixel in the image has an initial brightness level that is within a range of brightness levels between a minimum brightness level and a maximum brightness level. For each brightness level within the range, the number of pixels that have the same initial brightness level is counted. The pixels are divided into at least two types by identifying the or each set of pixels having initial brightness levels in which each of a plurality of adjacent ones of said brightness levels has more pixels than a threshold number. The pixels of the plurality of adjacent ones of said brightness levels are treated as a first type. The remaining pixels are treated as a second type. For the or each set of pixels of the first type, contrast enhancement is carried out separately on those pixels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.