Method for adaptively thresholding grayscale image data
US5410617A · kind A · utility
29Cited by
8References
18Claims
0Family size
Assignee
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Key dates
| Filing date | Nov 10, 1993 |
| Grant date | Apr 25, 1995 |
| Priority date | — |
| Expiry date | Nov 10, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V30/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of generating a remapping function for use in converting near-photographic document image pixel gray level data lying in a first range of gray level values to higher contrast, background-suppressed pixel gray level data lying in a second more limited gray level range. Global document information, such as a histogram of all the document's original pixels, is used to generate at least one threshold gray level value and to determine the shape of the remapping function on either side of the threshold. Preferably, the remapping function is implemented by a look-up table addressed in accordance with the original pixel data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.