jandreas@pro-graphics.cts.com (Jason Andreas) (06/02/90)
I'm in need of some software (specifically source code) for RGB-=>CMYK
conversion. If someone could post a phone number or FTP site where such a
thing is available, please do so.
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Internet: jandreas@pro-graphics.cts.comdarcy@druid.uucp (D'Arcy J.M. Cain) (06/04/90)
In article <2967@crash.cts.com> jandreas@pro-graphics.cts.com (Jason Andreas) writes: >I'm in need of some software (specifically source code) for RGB-=>CMYK >conversion. If someone could post a phone number or FTP site where such a >thing is available, please do so. > Perhaps this should be added to the FAQ. This depends on how you store colour information but assuming each of the RGB and CMYK components is an integer from 0 to 255 then you have to do the following: Convert to CMY C = 255 - R M = 255 - G Y = 255 - B Find the black level. This is simply the smallest of C, M or Y. Subtract this value from each of C, M and Y. Note that this means that even with black included, there is never more than 3 components for a colour. There are further enhancements which involve adjusting for each of the inks but this varies with different printing processes. -- D'Arcy J.M. Cain (darcy@druid) | Government: D'Arcy Cain Consulting | Organized crime with an attitude West Hill, Ontario, Canada | (416) 281-6094 |