Title:
METHOD AND APPARATUS FOR COLOR IMAGE PROCESSING
Document Type and Number:
WIPO Patent Application WO/1991/008520
Kind Code:
A1
Abstract:
A method for color image processing and an apparatus therefor whereby a percent dot area is decided in the color printing with the use of inks of four colors, i.e. yellow, magenta, cyan and sumi (China ink). In color printing, most colors can be printed theoretically by superimposing three color inks Y, M and C. However, color printing is made generally by four colors by adding sumi ink (K) to these inks. When the four colors including sumi ink are used, it is difficult to decide a percent dot area of each color for reproducing a target color, and satisfactory color reproduction cannot always be achieved with the percent dot area that is determined by a conventional method. According to the present invention, 16 kinds of color dots of the Y, M, C and K inks to be used for actual printing are measured for their tristimulus values which are introduced to a quaternary quartic Neugebauer equation. Thus, the percent dot areas AY, AM, AC, AK of the individual inks are determined for reproducing accurately each target color XYZ. Color printing with good color reproduction is realized using the area ratios determined by the above method.
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Inventors:
SAYANAGI KAZUO (JP)
NAKAMURA CHIHO (JP)
NAKAMURA CHIHO (JP)
Application Number:
PCT/JP1990/001568
Publication Date:
June 13, 1991
Filing Date:
December 04, 1990
Export Citation:
Assignee:
SHAKEN KK (JP)
International Classes:
G03F5/00; H04N1/46; H04N1/48; H04N1/52; H04N1/60; (IPC1-7): G03F5/00
Foreign References:
| JPS5994759A | 1984-05-31 |
Other References:
Nihon Insatsu Gakkai-hen "Presswork Engineering Manual" July 20, 1983 (20. 07. 83), Gihodo Shuppan (Tokyo), p. 273-275.
See also references of EP 0456832A4
See also references of EP 0456832A4
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