Image noise reduction
US7324701B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 22, 2003 |
| Grant date | Jan 29, 2008 |
| Priority date | — |
| Expiry date | Feb 17, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/58
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image processing apparatus determines whether or not a target pixel TP which is the object of the smoothing process is an edge-forming pixel based on the edge level (gradient g). If the pixel is determined to be an edge-forming pixel, the smoothing process employs an elliptical median filter instead of a moving average filter. The median filter MF has an elliptical reference area RA that is tilted (angled) to match the orientation of the edge Eg (edge angle), allowing the smoothing process to be carried out without compromising the edge components. The angle of the edge Eg is thus determined in the smoothing process, a median filter MF with an angle matching the determined edge angle is selected, and the selected median filter MF is used to carry out the smoothing process on target pixels TP which are edge-forming pixels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.