Page 126 - Graphic Design and Print Production Fundamentals

4.9 A Review of the Profile Classes

Alan Martin

We’ve now touched on the four types or classes of profiles: display, input, output, and device link. What
traits do they have in common? They are:

• Specified by ICC-defined file formats

• Contain colour tables

• Have device colour values associated with device independent colour values (PCS)
• Use a measuring device (spectrophotometer) and targets for creation

• Require a specified rendering intent
• Have standard OS library locations

There are also some unique characteristics for each profile class that help define the role they play in the
overall colour management process. The display class of profiles:

• Have no separate, tangible target: the device ‘is’ the target
• Can affect device behaviour

• Are mostly integrated with device calibration

The input class of profiles:

• Are unidirectional: A to B table only (device values to PCS)
• Are able to exclude any external measuring (with a supplied TDF)

• Ensure that the target’s job is tell us how the device ‘sees’ the target

Output (and device link) class of profiles:

• Use CMYK (versus RGB for display and input)
• Have black handling settings

• Have the largest and most complex colour tables
• Ensure the target’s job is to tell us how the device ‘makes’ the target

• Provides preview capability for upstream editing

We also discussed the functions of a profile in the colour equation. The two functions are source and
destination. A source profile is a profile used to convert device dependent RGB or CMYK information
to a device independent colour space (Lab). A destination profile is a profile used to convert information
from a device independent colour space (Lab) into a device dependent colour space of an output device

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