Method and apparatus for producing a contrast enhanced image
US8411983B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 31, 2007 |
| Grant date | Apr 2, 2013 |
| Priority date | — |
| Expiry date | Mar 13, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T5/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for enhancing an input image to produce a contrast enhanced output image is disclosed. The method involves producing a contrast value for each pixel in the input image, the contrast value being proportional to an intensity gradient between each respective pixel and at least one pixel adjacent the respective pixel. The method also involves selecting pixels in the input image having respective contrast values that meet a first criterion, thereby forming a selected plurality of pixels and producing a frequency distribution of intensity values of the selected plurality of pixels. The method further involves selecting at least one range of intensity values in the frequency distribution that meet a second criterion, thereby producing a selected range of intensity values for enhancement. The method also involves producing the contrast enhanced output image by at least one of (i) expanding pixel intensity values in the input image that fall within the selected range of intensity values; and (ii) compressing pixel intensity values in the input image that fall outside the selected range of intensity values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.