Method for adjusting image contrast
US7340091B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 7, 2005 |
| Grant date | Mar 4, 2008 |
| Priority date | — |
| Expiry date | Aug 12, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T5/92
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for adjusting image contrast has the steps of constructing a luminance histogram of an original image; acquiring an image characteristic of the luminance histogram; judging whether there is a peak wave or deviation of luminance existed in that image characteristic; determining a control point after performing a specific algorithm; deriving a linear equation from the control point and a contrast adjusting value in a Cartesian coordinate system; establishing a gamma table from the correspondent relationship between the horizontal and vertical axis in the coordinate, where the relationship can be calculated according to the linear equation; and finally generating a luminance value from the gamma look-up table using the input luminance of each pixel in the original image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.