Method and apparatus for local standard deviation based histogram equalization for adaptive contrast enhancement
US7835587B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 2006 |
| Grant date | Nov 16, 2010 |
| Priority date | — |
| Expiry date | Sep 15, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30196
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Various embodiments for image contrast enhancement are described. In one or more embodiments, adaptive contrast enhancement may be realized by performing local standard deviation (LSD) based histogram equalization. In such embodiments, luminance (Y) values of an image may be grouped into one of several luminance regions, with each luminance region defining an LSD threshold. An LSD value may be calculated for each pixel within a particular luminance region and then compared to the LSD threshold for the particular luminance region. If the calculated LSD value for a pixel is smaller that the defined LSD threshold, then the pixel is not counted as a population for histogram equalization calculation. Otherwise, the pixel is counted as one population. Other embodiments are described and claimed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.