US 6,983,076 B2 | ||
Control system for digital de-screening of documents | ||
Donald J. Curry, Menlo Park, Calif. (US); Doron Kletter, San Mateo, Calif. (US); and Asghar Nafarieh, Menlo Park, Calif. (US) | ||
Assigned to Xerox Corporation, Stamford, Conn. (US) | ||
Filed on Jul. 01, 2002, as Appl. No. 10/188,026. | ||
Prior Publication US 2004/0001642 A1, Jan. 01, 2004 | ||
Int. Cl. G06K 9/40 (2006.01); H04N 1/405 (2006.01) |
U.S. Cl. 382—260 | 23 Claims |
1. A method for controlling de-screening operation in a de-screening system, the de-screening system including a bank of filters,
the bank of filters receiving an image signal and producing a set of filter output signals, the method comprising the operations
of:
(1) receiving, via a contrast module, a filter output signal from a first filter in a bank of filters and producing a contrast
signal, the first filter being one of the filters having larger filter spans in the bank of filters;
(2) receiving, via a halftone estimate module, the image signal and a second filter output signal from a second filter in
the bank of filters, the second filter being one of the filters-having smaller filter spans in the bank of filters, and producing
an estimated frequency signal and a halftone weight signal; and
(3) receiving, via a pixel control module, the contrast signal from the contrast module and the estimated frequency signal
and the halftone weight signal from the halftone estimate module, and producing the first control signal, the first control
signal including information regarding which of the filter output signals are to be blended and the proportion of blending.
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