The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 03, 2007
Filed:
Dec. 12, 2002
Applicants:
Jeng-nan Shiau, Webster, NY (US);
Ying-wei Lin, Penfield, NY (US);
Inventors:
Jeng-nan Shiau, Webster, NY (US);
Ying-wei Lin, Penfield, NY (US);
Assignee:
Xerox Corporation, Stamford, CT (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04N 1/405 (2006.01);
U.S. Cl.
CPC ...
Abstract
A method to detect frequency and angle of a binary halftone pattern. The method employs an exclusive-or operation which is applied locally to a region of a binary bit map and its spatially shifted version. The resulting bits from the exclusive-or operation are summed over the region. The exclusive-or operation is repeated for a range of shift values. In a halftone region, the shift at which the minimum sum occurs reflects the angle and the frequency of the halftone.