Method of enhancing the tone scale of a digital image to extend the linear response range without amplifying noise
US6937775B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 2002 |
| Grant date | Aug 30, 2005 |
| Priority date | — |
| Expiry date | Feb 18, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/20064
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method of processing a digital image to improve contrast, the digital image being derived from an image captured by a recording medium having a nonlinear response to light, includes the steps of: applying a spatial filter to the digital image to produce a noise reduced digital image; subtracting the noise reduced digital image from the digital image to produce a difference digital image; applying a tone scale function to the noise reduced digital image to produce a tone scale adjusted digital image having the appearance of being derived from an image captured by a recording medium having a linear response; and combining the difference digital image with the tone scale adjusted digital image to produce a processed digital image, whereby the contrast of the digital image is improved without amplifying noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.