Method for determining document background for adjusting the dynamic range of an image of the document
US6198845A · kind A · utility
36Cited by
5References
29Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1997 |
| Grant date | Mar 6, 2001 |
| Priority date | — |
| Expiry date | Jul 1, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/10008
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The background grey-level of a document is determined based on the gain of the document. A histogram is generated and compressed. The standard deviation of the distribution curve of the compressed histogram is determined. A gain factor is determined using the mean and standard deviation. Using the background grey-level, the dynamic range of the document is adjusted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.