Fixed pattern noise compensation with low memory requirements
US6995346B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 2002 |
| Grant date | Feb 7, 2006 |
| Priority date | — |
| Expiry date | Sep 12, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/672
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and a system for the compensation of Fixed Pattern Noise (FPN) in digital images have been achieved. The FPN compensation is based on processing done during the production of said images. The fixed pattern noise is here defined as the fixed pattern seen in the individual pixel offsets. The fixed pattern noise is uncorrelated noise but it has a statistical distribution that can be scaled to fit all images. The general idea is to measure the distribution for each individual camera, compress it, and save it in the module. For each image that is then taken with the module the noise pattern can be retrieved and rescaled to fit the image. Covered pixels are employed to normalize the FPN data to the current frame. In order to minimize memory requirements a compression scheme has to be used. A method combining a quantization step with a non-lossy compression is used. The black level is corrected for as part of the operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.