Adaptive postprocessing system for reducing blocking effects and ringing noise in decompressed image signals
US5883983A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 1996 |
| Grant date | Mar 16, 1999 |
| Priority date | — |
| Expiry date | Oct 9, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/86
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An adaptive signal filtering method is provided to reduce blocking effects caused by decompression the block-based compressed images. The method includes the steps of generating binary edge map information by globally thresholding and locally thresholding the decompressed image; determining whether the binary edge map information within a filter window corresponding to respective pixels corresponds to a homogeneous area or an edge area, by using the binary edge map information corresponding to the filter window; generating a filtered pixel value corresponding to a respective pixel using the filter window which has a predetermined first weight factors for the homogeneous area when the binary edge map information is determined to be a homogeneous area in the determining step; adapting a predetermined second weight factors according to binary edge map information included in the filter window when the binary edge map information determined as an edge area in the second step; and generating a filtered pixel value for the respective pixel, using the filter window which has adapted second weight factors in said adapting step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.