Autofocus with confidence measure
US8027582B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 2009 |
| Grant date | Sep 27, 2011 |
| Priority date | — |
| Expiry date | Mar 30, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/10148
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Autofocusing is performed in response to a weighted sum of previous blur difference depth estimates at each focus adjustment iteration. Variance is also determined across both past and present estimations providing a confidence measure on the present focus position for the given picture. Focus adjustment is repeated until the variance is sufficiently low as to indicate confidence that a proper focus has been attained. The method provides more accurate and rapid focusing than achieved by the best current depth-based techniques, such as those utilizing most recent depth estimation to determine the next lens position. In contrast to this, the present apparatus and method combines all previous depth estimation results in the autofocus process to determine the next lens position based on statistical models and confidence measure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.