Low-complexity deblocking filter
US7227901B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 2002 |
| Grant date | Jun 5, 2007 |
| Priority date | — |
| Expiry date | May 31, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/176
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of filtering to remove coding artifacts introduced at block edges in a block-based video coder, the method having the steps of: checking the content activity on every line of samples belonging to a boundary to be filtered and where content activity is based on a set of adaptively selected thresholds determined using Variable-Shift Table Indexing (VSTI); determining whether the filtering process will modify the sample values on that particular line based on said content activity; and selecting a filtering mode between at least two filtering modes to apply on a block boundary basis, implying that there would be no switching between the two primary modes on a line by line basis along a given block boundary. The two filtering modes include a default mode based on a non-recursive filter, and a strong filtering mode which features two strong filtering sub-modes and a new selection criterion that is one-sided with respect to the block boundary to determine which of the two strong filtering sub-modes to use. The two strong filtering sub-modes include a new 3-tap filter sub-mode and a 5-tap filter sub-mode that permits a more efficient implementation of the filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.