Method for using flash to assist in focal length detection
US8199247B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 5, 2010 |
| Grant date | Jun 12, 2012 |
| Priority date | — |
| Expiry date | Feb 24, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/74
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for assist in focal length detection is adapted to a digital camera having a flash. The method includes the following steps. First, the flash of the digital camera is actuated and an image having a face portion is captured. Afterwards, an exposure feature value of the face portion in the image is calculated. A focus range comparison table is looked up according to the exposure feature value to obtain an initial focus position. Then, a focus procedure is performed according to the initial focus position to obtain a target focal length. After the target focal length is obtained, a flash feature value of the image is further calculated, and a guide number (GN) and a diaphragm value are set according to the flash feature value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.