Chapter 6 ― More on Color Management

Color management is, “the ability to reproduce images and graphics from various input devices on various output devices while maintaining color fidelity.” Why do we need the ICC profile specification now when we’ve been doing color management all along? The emergence of personal computers and desktop systems, as well as a market increase in the demand for color, has increased the need for color. Now photographers, designers, and others need to understand color, where in the past it was not a required skill.

The Basics of a Color Management System. Color management requires three components: profiles for input and output devices, color management engines, and software to interpret data and profiles for output. Color management can reduce production costs by reducing waste and can improve color consistency as well as proofing. Color management is not a substitute for measurement and process control. You have to get your press under control in order to be able to use profiles. Color management is also useful for spot color management and high fidelity color applications. In the case of spot colors, in the absence of spot color proofing colorants, color management can be used to create the “best fit” CMYK interpretation of the spot color.

For open color management to work all devices must automatically create and use device profiles, all operating systems must support the ICC profile standard, all graphics and page layout applications must call on ICC profiles, and color management must become transparent to the end user.

ICC Profiles employ a standard reference media. This “media” is an idealized media, but NOT a print media. The “white point” is 85% reflectance and the black point is .35% reflectance.  All graphic arts profiles need three profile types: saturation, colorimetric, and perceptual, and there should be CMYK-to-PCS and PCS-to-CMYK profiles as well. Colorimetric data maintains absolute values. Perceptual data maintains color “intent” or relative colorimetric data. Saturation data, not normally processed within the graphic arts, expands the out edge of the gamut from one device to another. ICC Profiles, as used by graphic arts, include information on gamut and tone scale compression, color separation methodology, black to color relationship method (UCR/GCR), and copyright material.

Color management will only be successful if everyone takes responsibility for calibration and management throughout the process. The color management objective of some printers is to save on cost by being able to put a lower cost person on scanning operations.

To make ICC profiles work in graphic arts application, the color management modules (CMM) provided by each manufacturer must be open and consistent. The profile data must support re-purposing. For more information on the ICC Color Profile specification visit http://www.npes.org.