| US 7,586,647 B2 | ||
| Halftone detection and removal | ||
| Timothy John Wark, The Gap (Australia); James Austin Besley, West Ryde (Australia); and James Philip Andrew, Waverton (Australia) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Jul. 06, 2005, as Appl. No. 11/174,590. | ||
| Claims priority of application No. 2004904242 (AU), filed on Jul. 29, 2004; and application No. 2004904250 (AU), filed on Jul. 29, 2004. | ||
| Prior Publication US 2006/0023259 A1, Feb. 02, 2006 | ||
| Int. Cl. H04N 1/40 (2006.01) | ||
| U.S. Cl. 358—3.06 [382/261] | 51 Claims |
| 1. A method for processing an image to detect halftone, said method comprising the steps of:
arranging said image into a plurality of bands each comprising a predetermined number of consecutive lines of pixels;
arranging each of said plurality of bands into a plurality of tiles of pixels;
selecting one of said plurality of tiles as a selected portion;
processing data relating to said selected portion, said processing comprising the sub-steps of:
quantizing data relating to said pixels in said selected portion;
assigning pixels that have the same value and that are adjacent to one another in said selected portion to a connected component;
determining the number of unique connected components in said selected portion; and
comparing said number of unique connected components to a threshold value; and
detecting halftone present in said selected portion based on a result of said processing step and on a result of processing
at least one other portion of said image.
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