| US 7,602,531 B2 | ||
| Halftone edge enhancement for production by an image forming device | ||
| James Ray Bailey, Georgetown, Ky. (US); and Khageshwar Thakar, Lexington, Ky. (US) | ||
| Assigned to Lexmark International, Inc., Lexington, Ky. (US) | ||
| Filed on Mar. 22, 2006, as Appl. No. 11/277,190. | ||
| Prior Publication US 2007/0223044 A1, Sep. 27, 2007 | ||
| Int. Cl. H04N 1/405 (2006.01) | ||
| U.S. Cl. 358—3.15 [358/3.27] | 18 Claims |
| 1. A method of processing a digital image for production by an image forming device, the digital image comprising a plurality
of elements, each element characterized by a range of pixel intensities represented in a first color depth, the method comprising:
for each element in the digital image, determining if the magnitude of a pixel intensity gradient between an element of interest
in a first window applied at each element and other elements in the first window satisfies a first predetermined condition;
classifying those elements satisfying the first predetermined condition in a first category;
creating a duplicate image by reducing the color depth of said digital image to a second color depth;
applying a filter to elements of the duplicate image corresponding to those elements that are classified in the first category
using a second window.
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