Visibility improvement in color video stream
US7428333B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 24, 2005 |
| Grant date | Sep 23, 2008 |
| Priority date | — |
| Expiry date | Jun 11, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/10024
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A new image enhancement process based on an integrated neighborhood dependent nonlinear approach for color images captured in various environments such extremely low lighting, fog or underwater. The new process is a combination of two independent processes: luminance enhancement and contrast enhancement. The luminance enhancement, also regarded as a process of dynamic range compression, is essentially an intensity transformation based on a specifically designed nonlinear transfer function, which can largely increase the luminance for dark regions of the image but only slightly change the luminance for the bright regions of the image. The contrast enhancement transforms each pixel's intensity based on the relationship between the pixel and its surrounding pixels. The output of the contrast enhancement is a power function of the luminance of the input image. The exponent of the power function is determined by the information obtained in the original luminance image, which is the ratio between the result of neighborhood averaging and the luminance of the center pixel. After contrast enhancement, the luminance image is converted back to a color image through a linear color restoration …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.