Method of improving a digital image
US5991456A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | May 29, 1996 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | May 29, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T5/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method of improving a digital image is provided. The image is initially represented by digital data indexed to represent positions on a display. The digital data is indicative of an intensity value I.sub.i (x,y) for each position (x,y) in each i-th spectral band. 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 ##EQU1## where S is the number of unique spectral bands included in said digital data, W.sub.n is a weighting factor and "*" denotes the convolution operator. Each surround function F.sub.n (x,y) is uniquely scaled to improve an 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 is filtered with a common function and then presented to a display device. For color images, a novel color restoration step is added to give the image true-to-life color that closely matches human observation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.