Non-linear adaptive image filter for filtering noise such as blocking artifacts
US6285801A · kind A · utility
106Cited by
5References
23Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 29, 1998 |
| Grant date | Sep 4, 2001 |
| Priority date | — |
| Expiry date | May 29, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/20192
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A filter reduces artifacts, such as grid noise and staircase noise, in block-coded digital images with image block boundaries. The type of filtering is determined after an estimation of the image global metrics and local metrics. For areas of the image near grid noise, the filter performs low pass filtering. For image fine details, such as edges and texture, no filtering is performed so that masking is avoided. The filter operates in intra-field mode and uses a fuzzy logic process, pixel deltas, and dual ramp generators to determine the horizontal and vertical length of a processing window surrounding an image block boundary.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.