De-blocking and de-banding filter with adjustable filter strength for video and image processing
US9445131B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 2015 |
| Grant date | Sep 13, 2016 |
| Priority date | — |
| Expiry date | Apr 10, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/186
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A novel de-blocking and de-banding filter and a related method of operation reduce and/or remove blocking and banding artifacts that originate from a low bitrate video compression. For filtering a luminance channel, the de-blocking and de-banding filter determines filtering needs and also adjusts filtering strengths based on a compression level (Qp) and a gray level of the video signal. For filtering a chrominance channel, the de-blocking and de-banding filter determines the filtering needs and adjusts the filtering strengths based on Qp alone. Preferably, the de-blocking and de-banding filter utilizes a low pass filter of adjustable strength at a border of a block perpendicular to the border or a band border. The adjustable strength of the de-blocking and de-banding filter is a function of the compression level (Qp) and/or the gray level of the video signal, but does not depend on a duration of the blocking and/or banding artifacts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.