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Tuesday, November 30, 2010

ICC Profiles

From http://people.csail.mit.edu/jaffer/Color/Dictionaries:

Section 10.14, "namedColor2Type", of Specification ICC.1:2004-10 (Profile version 4.2.0.0):

The namedColor2Type is a count value and array of structures that provide colour coordinates for 7-bit ASCII colour names. For each named colour, a PCS and optional device representation of the colour are given. Both representations are 16-bit values and PCS values shall be relative colorimetric. The device representation corresponds to the header's "colour space of data" field. This representation should be consistent with the "number of device components" field in the namedColor2Type. If this field is 0, device coordinates are not provided. The PCS representation corresponds to the header's PCS field. The PCS representation is always provided. Colour names are fixed-length, 32-byte fields including null termination. In order to maintain maximum portability, it is strongly recommended that special characters of the 7-bit ASCII set not be used.

This namedColor2Type specification dates back to version 3.2 (1995), perhaps earlier. Only XYZ and L*a*b* colors are supported. Although version 4.2 defines "multiLocalizedUnicodeType", namedColor2Type is restricted to ASCII (and length less than 32.B). The colors in this table are specific to the profiled device. So namedColor2Type appears to be intended for including "spot" colors (such as from Pantone) in a device profile, not for device-independent color dictionaries.

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