Screen filtering boundary detection for noise filtering prior to image compositing
US5557339A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 9, 1994 |
| Grant date | Sep 17, 1996 |
| Priority date | — |
| Expiry date | May 9, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/272
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus which allows different amounts of filtering to be applied to specific parts of a foreground image, thus minimizing visible noise in the backing area, while preserving fine detail information of foreground objects. The method and apparatus identify three areas within the foreground, namely unobscured backing (screen) area, screen to foreground subject transition area, foreground subject area. The area where full amount of filtering is desired is the backing area, including shadows. This is the area where the background image will be added, and if noise is present in this area, it will be added to the background image. The transition area from the screen to the foreground object requires variable amounts of filtering, depending on the width of the transition. For sharply focused edges and very fine detail, the transition width is very small, and any filtering applied there will cause blurring and softening of these edges and details. Therefore, no filtering is applied to those areas. For out of focus and moving objects, the transition width is large, and no foreground detail information is visible. In these areas, a variable amount of filtering is applied, base…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.