Test chart for determining the image quality of an optical scanner
US6222934A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 17, 1998 |
| Grant date | Apr 24, 2001 |
| Priority date | — |
| Expiry date | Jul 17, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/6033
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A test chart printed on the front end of a calibration paper readable by an optical scanner for image quality test. The test chart comprises missing line test patterns for showing line missed in an image; gray-level test patterns located at the left side, the right side and at the center of said test chart for showing color balance, color consistency, black and white effects, and step transition of an image; resolution test patterns each located at the left side, the right side and at the center of said test chart for showing resolution of an image read by said optical scanner; and scaling-up test patterns each located at the front end on the two sides of said test chart and at the bottom of said test chart for showing the horizontal scaling up and vertical scaling up of an image. The patterns on the test chart are so compact and well designed that they can be read by an optical scanner by only one pass of image reading. Moreover, from the image of the test chart, a computer program can efficiently perform image quality tests to determine the quality of an optical scanner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.