System and method for optimizing tonal resolution in an optical scanner
US5726771A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1994 |
| Grant date | Mar 10, 1998 |
| Priority date | — |
| Expiry date | Oct 31, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4072
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The tonal resolution of an image scanner is improved by adjusting the dynamic range of an analog-to-digital converter of the scanner. A preview scan of the image is made. The image data from the preview scan is then analyzed to determine a maximum intensity and a minimum intensity. The value of the maximum intensity is used to set a white intercept of the image scanner such that a maximum digital value of the analog-to-digital converter corresponds to the maximum intensity present in the image data from the preview scan. The minimum intensity is used to set a black intercept of the image scanner such that the minimum intensity in the image data from the preview scan corresponds to the minimum digital number output by the analog-to-digital converter. Tonal resolution of the image scanner is optimized then by performing a final scan of the image with the analog-to-digital converter programmed to reflect the new white intercept and black intercept values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.