Autoexposure methodology in a digital camera
US7176976B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 15, 2002 |
| Grant date | Feb 13, 2007 |
| Priority date | — |
| Expiry date | Oct 4, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/76
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An improved method for automatic exposure control at a digital camera is described. In response to a user request for capture of a digital image, image data is captured on the camera's image sensor. The captured image data includes pixel values of brightness of pixels of the image sensor. A histogram of pixel values is generated based upon brightness of pixels of the image sensor. The histogram that is generated is then evaluated to determine whether an image is overexposed or underexposed. Coarse exposure settings for capture of a digital image are automatically generated based upon scaling the histogram of pixel values towards the midpoint of a pre-selected interval. The coarse exposure settings and image data that have been captured are evaluated to determine whether light sources are present. In the event that light sources are determined not to be present, the coarse exposure settings are adjusted based upon not scaling said histogram beyond the largest histogram value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.