Method for enhancing compressibility and visual quality of scanned document images
US6731821B1 · kind B1 · utility
42Cited by
12References
3Claims
0Family size
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Key dates
| Filing date | Sep 29, 2000 |
| Grant date | May 4, 2004 |
| Priority date | — |
| Expiry date | Aug 27, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V30/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system and method of image processing for smoothing, denoising, despeckling and sharpening scanned document images which is performed prior to a compression. The scanned image is selectively smoothed by anisotropic diffusion filtering in a single iteration with a 3×3 kernel, which provides denoising, edge-preserving smoothing. The smoothed image data is then selectively sharpened using variable contrast mapping that provides overshoot-free variable-sharpening and despeckling. Image quality is improvides while increasing compressibility of the image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.