Method of correcting the measured reflectance of an image acquired by an image acquisition device for the integrating cavity effect
US5790281A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1996 |
| Grant date | Aug 4, 1998 |
| Priority date | — |
| Expiry date | Oct 2, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4076
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
This invention discloses a method of correcting the measurement of the amount of light reflected by a document that is being processed by a digital image acquisition apparatus. A typical image acquisition apparatus measures the amount of light reflected from the surface of the original document and sets a corresponding set of electrical signals to a printing or storage module. Image acquisition usually requires illuminating the original document with a reflecting cavity, which causes the measurement of the amount of light present on the surface of the document to become distorted. The method disclosed by the present invention corrects this phenomenon by calculating the amount of light that reaches the surface of the original document by being reflected from the illumination system and the surrounding cavity. This allows the measured reflectance to be corrected, and the true reflectance to be used for subsequent output or storage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.