Automatic flicker frequency detection device and method
US7750949B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 13, 2007 |
| Grant date | Jul 6, 2010 |
| Priority date | — |
| Expiry date | Jul 23, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/70
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image device, such as a digital camera, detects specific repeating patterns of signal variations by processing columnar information from the device's two-dimensional sensor array used to generate images. In one embodiment, the columnar information is derived from calculating row averages for two image frames, with each row average being a computed average of the multiple signal intensities generated from some or all of the sensors within a particular row. After the columnar information is determined for each of the two frames, a difference signal is generated as a sequence of the differences between the row averages for the first frame and the row averages for the second frame. This row averaging and frame differencing removes a large percentage of the signal energy that is not a result of the artifact of interest, such as the flicker generated by illumination having intensity fluctuations at 100 Hz or at 120 Hz. In some embodiments of the invention, the row averaging and/or the frame-to-frame comparison are deleted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.