Method for enhancing compressibility and visual quality of scanned document images
AssigneeHewlett-Packard Development Company, L.P.
InventorsRon P. Maurer, Danny Barash
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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.
Claims3
A method of processing image data including pixel intensity values comprising the steps of:
- selectively smoothing the image data to generate selectively smoothed image data wherein areas characterized as edges within the selectively smoothed image data are essentially preserved;
- selectively sharpening the selectively smoothed image data using variable contrast stretching.
Dependencies are inferred from the claim text.