Digital image noise reduction of luminance and chrominance based on overlapping planar approximation
US5563963A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 1991 |
| Grant date | Oct 8, 1996 |
| Priority date | — |
| Expiry date | Oct 23, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/20192
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention reduces noise in digital photographic images based on the assumption that images may be decomposed into two types of regions, smooth regions and edge regions. Smooth regions are areas of the image lacking any sharp detail, such as blue sky. Edge regions are regions containing sharp detail, such as edges and textured regions (such as grass). The present method reduces noise in the smooth regions by a mathematical blurring technique based on least squares regression. The blurring does not degrade the sharpness of the image, because there are no sharp details in the smooth regions. Edge regions are left undisturbed to maintain sharpness, but the noise is less noticeable in those regions than in the smooth regions. The method operates upon the luminance and chrominance component of a digital image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.