Patent ID: 7847975

Claim:
A method of converting black to composite black in digital print comprising: (a) providing a digital color print engine; (b) using the color print engine for establishing a lightness adjustment factor K o from black (0, 0, 0 K in ) for the input image; (c) using the print engine for setting initial values of cyan (C o ), magenta (M o ), and yellow (Y o ) equal to K o ; (d) using the print engine for converting C o , M o , Y o to values of C 1 , M 1 , Y 1 , K 1 by GCR strategy; (e) using the print engine for determining corresponding values of Gray Balance Adjustment C out , M out , Y out , K out for values of C i , M 1 , Y 1 , K 1 ; and, (f) inputting the values of C out , M out , Y out , K out to the digital color print engine.