Automatic estimation and correction of vignetting
US8577140B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 29, 2011 |
| Grant date | Nov 5, 2013 |
| Priority date | — |
| Expiry date | Jan 19, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/61
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Various embodiments pertain to image correction techniques that automatically estimate and correct vignetting based upon a single image. In various embodiments, a local gradient is estimated and the radial component of the gradient is ascertained. Radial components of gradients are correlated with a radius of the pixel from the optical center of the image, and can be utilized to estimate an attenuation due to vignetting. In some embodiments, a tangential component of a difference of gradients is also ascertained and correlated with the radius for use in estimating the attenuation. Attenuation due to vignetting can be calculated through the application of a polynomial regression to a plot of the radial components versus radius. In various embodiments, the image can be corrected by inverting the attenuation in the image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.