Method for estimating and adjusting digital image contrast
US5822453A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1996 |
| Grant date | Oct 13, 1998 |
| Priority date | — |
| Expiry date | Dec 10, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4074
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of estimating the scene contrast from a digital image, the method comprises the steps of: forming a Laplacian histogram distribution; determining, from the Laplacian histogram, first and second thresholds which eliminate substantially uniform areas or a substantially textured portion of the digital image; selecting pixels which are based on the first and second thresholds from the digital image; forming a histogram from the sampled pixels; computing a standard deviation of the sampled histogram; and estimating contrast of the digital image by comparing the computed standard deviation with a predetermined contrast for determining contrast of the input image in relationship with the predetermined contrast.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.