Histogram-based automatic gain control method and system for video applications
US6750906B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 1998 |
| Grant date | Jun 15, 2004 |
| Priority date | — |
| Expiry date | May 8, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/72
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image processor system for a charge coupled device (CCD) or CMOS imaging system includes a histogram-based automatic gain control (AGC) circuit which first controls gain by adjusting said CCD system and then for yet a higher gain level makes gain adjustments in said CDSVGA circuit and a digital gain circuit to produce a combined target gain level. A processing system for an imager device includes a camera system for producing an imager signal, a correlated double sample (CDS) circuit for receiving data from an imager, a variable gain amplifier (VGA), an analog-to-digital converter (ADC) coupled to said CDS circuit, a digital gain circuit (DGC) coupled to said ADC, and an automatic gain control (AGC) circuit coupled to said DGC for controlling the CDS circuit and the DGC, as well as shutter timing for shutter gain.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.