Image sensing apparatus and shading correction method
US6075621A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 1997 |
| Grant date | Jun 13, 2000 |
| Priority date | — |
| Expiry date | Aug 6, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/401
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A high-quality image is recorded in precise correspondence with the image information of a document sensed by an image scanner without producing an error in gray level. Control means performs a gray level correction on the image information sensed by the image scanner in accordance with the surface gray level information of a reference plate which has been sensed in advance by the image scanner thereby generating recording information corrected in gray level, wherein the gray level correction is performed when the recording information is generated from the image information thereby making compensation not only for the shading error but also for gray level errors due to other factors so that an image is recorded in exact correspondence with the sensed image information of the document without having an error in gray level. Correction values are set for each sensing element of the image scanner so that the corrected output value of each sensing element obtained in accordance with said correction values becomes proportional to the brightness. The image information sensed via the image sensing elements is corrected in accordance with the above correction values thereby generating a co…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.