US 7,321,448 B2
Color proofing method and apparatus, and recorded medium on which color proofing program is recorded
Nobukatsu Nishida, 31-27, Nango 2-chome, Otsu-shi, Shiga (Japan); Kazuyuki Uragami, 7-10, Higashitsukamoto-cho, Shimogamo, Sakyo-ku, Kyoto-shi, Kyoto 606-0855 (Japan); Makoto Ito, 2-13-403, Tomioka 2-chome, Urayasu-shi, Chiba 279-0021 (Japan); and Naoto Takeda, Kyoto (Japan)
Assigned to Sagawa Printing Co., Ltd., Kyoto (Japan); Nobukatsu Nishida, Shiga (Japan); Kazuyuki Uragami, Kyoto (Japan); Makoto Ito, Chiba (Japan); and Fuso Precision Co., Ltd., Kyoto (Japan)
Filed on Mar. 16, 2006, as Appl. No. 11/377,149.
Application 11/377149 is a division of application No. 10/052122, granted, now 7,123,379, previously published as PCT/JP99/03886, filed on Jul. 19, 1999.
Prior Publication US 2006/0251296 A1, Nov. 09, 2006
Int. Cl. H04N 1/60 (2006.01); H04N 1/409 (2006.01); G06K 9/00 (2006.01); G03F 3/08 (2006.01)
U.S. Cl. 358—1.9  [358/518; 358/3.26; 382/162; 382/167; 382/112] 2 Claims
OG exemplary drawing
 
1. A color proofing method for improving the color reproducibility of printed matter to be produced by a printing press in proof print produced by a proof press, the color proofing method comprising the step of:
correcting proof printing image data, in which each of levels of monochromatic color gradation of black on the printed matter is represented on the proof print, out of the proof printing image data over the entire color space in a subtractive process resulting from color matching between proof print produced by the proof press and the printed matter to be produced by the printing press in such a manner that a part having a black ink area factor of 100% on the printed matter is represented only with black ink also on the proof print, but that a part other than the part having a black ink area factor of 100% on the printed matter is represented on the proof print by using under color removal, to thus reproduce, on the proof print, the representing characteristics of the black ink on the printed matter; and,
wherein the step of correcting the proof printing image data includes the steps of:
finding min(C100, M100, Y100) from color values (C100, M100, Y100, Bk100) of the proof printing image data for representing, on the proof print, the part having the black ink area factor of 100% on the printed matter, to thus determine a new value P of Bk100;
finding an addition value α100 for Bk100 in accordance with the following equation:
α100=min(C100, M100, Y100)×(P−Bk100)/min(C100, M100, Y100),
wherein 1≤P≤100;
adding the addition value α100 to Bk100 as well as setting all of C100, M100 and Y100 to 0; and
repeating, with respect to n from 99 to 1, the following steps of:
determining min(Cn, Mn, Yn) from color values (Cn, Mn, Yn, Bkn,) of the proof printing image data for representing, on the proof print, a part having a black ink area factor of n % on the printed matter;
determining an addition value αn with respect to Bkn in accordance with the following equation:
αn=(min(Cn, Mn, Yn)−(100−n))×(P−Bk100)/min(C100, M100, Y100),
wherein 1≤P≤100, to thus add the addition value αn to Bkn; and
obtaining respective reduction values βn, γn, δn of Cn, Mn and Yn in accordance with the following equations:
βnn×((P−Bk100)/C100),
γnn×((P−Bk100)/M100), and
δnn×((P−Bk100)/Y100),
wherein 1≤P≤100, to thus subtract the reduction values βn, γn, and δn, and Cn, Mn and Yn, respectively.