Method of improving a digital image as a function of its dynamic range
US6834125B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jun 25, 2001 |
| Grant date | Dec 21, 2004 |
| Priority date | — |
| Expiry date | Jan 25, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T5/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention is a method of processing a digital image that is initially represented by digital data indexed to represent positions on a display. The digital data is indicative of an intensity value Ii(x,y) for each position (x,y) in each i-th spectral band. A classification of the image based on its dynamic range is then defined in each of the image's S spectral bands. The intensity value for each position in each i-th spectral band is adjusted to generate an adjusted intensity value for each position in each i-th spectral band in accordance with where Wn is a weighting factor, “*” is the convolution operator and S is the total number of unique spectral bands. For each n, the function Fn(x,y) is a unique surround function applied to each position (x,y) and N is the total number of unique surround functions. Each unique surround function is scaled to improve some aspect of the digital image, e.g., dynamic range compression, color constancy, and lightness rendition. The adjusted intensity value for each position in each i-th spectral band of the image is then filtered with a filter function that is based on the dynamic range classification of the image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.