Techniques for identifying and reducing block artifacts
US8542751B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 2010 |
| Grant date | Sep 24, 2013 |
| Priority date | — |
| Expiry date | Jul 9, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/14
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Techniques are described that can be used to identify blocking artifacts in both vertical and horizontal directions. For blocking artifacts in a vertical direction, a horizontal gradient is determined for a pixel. Gradient smoothing is performed for pixels in the row of the pixel. A ratio of the horizontal gradient over the gradient smoothing is determined. Any pixel with a ratio above a threshold and in a segment with a length that exceeds a threshold length as potentially having block artifacts. Each column with pixels that potentially have block artifacts is inspected to determine whether a number of block artifacts in the column are a local maximum and whether there is a sufficient number of blocking artifacts in the column. Columns that satisfy both conditions are considered to include blocking artifacts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.