Chromatic Adaptation Transform (CAT)

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

A CIE-based color space may be ICCBased or one of the spaces named in Other CIEBased color spaces. These colors is color rendered using either a destination ICC profile or a CRD, depending on the color configuration and whether the job contains transparency color. For more information see Transparency color management.

If the color is rendered with an ICC destination profile, the RIP applies a CAT using the matrix in CATMatrix from set-reproduction (see CATMatrix in setreproduction). The source white point of the CAT is either the illuminant of the ICC profile (ICCBased) or the WhitePoint of the CSA (other color spaces). The destination white point of the CAT is the illuminant of the ICC destination profile. The default CATMatrix is Von Kries, but it is common to use the Bradford matrix instead.

If the color is rendered with a CRD configured as a Legacy CRD (see Legacy CRDs), the CAT that is applied is the same as above except that the destination white point is the WhitePoint from the CRD.

If set-reproduction is not used in the color configuration, it is likely that color is rendered with the CRD from the graphics state. The PQR functionality of the CRD normally contains the CAT. This is applied as described in section 7.1.2 of [RB3].

For color transforms that are composed of conformant ICC profiles, a CAT won't be applied because all conformant ICC profiles use the D50 illuminant, meaning that both the source and destination have the same white point.