Illumination compensation using built-in reference
US6744469B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 13, 1999 |
| Grant date | Jun 1, 2004 |
| Priority date | — |
| Expiry date | Dec 13, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/044
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and system provide for real-time compensation of an imaging system for variations in illumination intensity. An illumination system provides reflected illumination, and a charge coupled device system directly detects the reflected illumination from the illumination system. The CCD system then converts the reflected illumination into illumination data and a host processor converts the illumination data into adjusted control data and final image data. The adjusted control data is based on an illumination profile and a reference illumination intensity. The reference illumination intensity is measured before each document with a compensation reference, and is compared to the illumination profile to adjust control parameters in a real-time mode. Directly measuring the illumination intensity with the CCD system allows for a reduction in parts, manufacturing steps, and errors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.