N-Color ICC profiles

This page applies to Harlequin v13.1r0 and later; both Harlequin Core and Harlequin MultiRIP.

The RIP supports the use of N-color profiles. They may be used in the /Profile and /InputColorSpace slots of the setreproduction operator, and in ICCBased color spaces. For example:

CODE

<<
  /Profile (iccprofiles/CMYKOG.icc) (r) file
>> setreproduction

uses the N-color profile, CMYKOG.icc, to convert color to an XG device that uses orange and green colorants in addition to CMYK. And this example:

CODE

<<
  /Profile (iccprofiles/WideCMYK.icc) (r) file
  /NextDevice <<
    /InputColorSpace [ /ICCBased (iccprofiles/Wide-CMYKOG.icc) (r) file ]
  >>
>> setreproduction

converts color to a wide gamut CMYK space using WideCMYK.icc, before using the DeviceLink profile, Wide-CMYKOG.icc, to convert to the same XG device. This subject is discussed in more detail in XG Color Management.

ColorantTableTag and ColorantTableOutTag

The RIP requires knowledge of the color components used in N-color profiles. Without this knowledge, the profile is rejected, and RIP throws an error.

Colorant information is supplied in N-color profiles using the standard ICC tags, colorantTableTag and colorantTableOutTag. These tags have the ICC signatures of clrt and clot respectively, and are often used synonymously:

colorantTableOutTag (clot) is required for the output colorants of a DeviceLink profile as shown as Wide-CMYKOG.icc in the above examples.
colorantTableTag (clrt) is required for other uses in N-color profiles. As shown as CMYKOG.icc in the above examples. It is also required when the N-colors are the input side of a DeviceLink profile, for example, in CMYKOGCMYK.icc as used in "N-Color ICC profiles".

It is possible to produce a DeviceLink profile that uses N-colors for both the input and output. The RIP requires these profiles to have both the colorantTableTag and colorantTableOutTag.

The ICC specification does not require these tags. N-color profiles without them are legal, but the RIP cannot use them.

N-Color ICC-based color spaces

N-color ICC-based color spaces are rarely used in jobs. When they are, they are internally converted to /DeviceN color spaces with the original ICC based used as the alternate space. These are then handled in the same manner as other /DeviceN color spaces. See Decomposing a DeviceN colorant list.