Image-reading device performing a white-shading correction by obtaining a peak value of average values of image data and read from a reference-white member in blocks as white-shading data
US6891648B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2001 |
| Grant date | May 10, 2005 |
| Priority date | — |
| Expiry date | Feb 15, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4076
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image-reading device is provided. The image-reading device comprises a photoelectric converting element reading a first image from a subject copy, a reference-white member functioning as a reference white used in a white-shading correction, reading means for reading a second image from a constant range on a surface of the reference-white member by using the photoelectric converting element, averaging means for dividing image data of the second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines and obtaining average values of image data of the lines in the blocks respectively, peak-value determining means for obtaining a peak value of the average values, and white-shading correcting means for performing the white-shading correction to image data of the first image by using the peak value as white-shading data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.