Luminance enhancement with overshoot reduction control based on chrominance information
US6453068B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 17, 1999 |
| Grant date | Sep 17, 2002 |
| Priority date | — |
| Expiry date | Sep 17, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/20192
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for digital image processing are provided for controlling luminance channel overshoot in response to FIR or other enhancement processing based upon chrominance. The luminance value of the enhanced digital image data for each pixel of an image is compared to corresponding local minimum and maximum luminance values of the non-enhanced image obtained from the neighborhood of the subject pixel. If an enhanced luminance value for a subject pixel falls outside the corresponding local minimum/local maximum luminance value range by a positive or negative overshoot amount, the enhanced luminance value is adjusted to attenuate the overshoot amount. The amount by which the enhanced luminance value for an enhanced pixel is adjusted varies depending upon the chrominance of the enhanced pixel. Also, the amount of overshoot attenuation can vary depending upon whether the enhanced luminance value is greater than the local maximum luminance value or less than the local minimum luminance value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.