Named color management

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

This section discusses the RIP's feature for replacing the alternate space and tint transform for individual spot colors using named color database (NCD) resources. It should be read in conjunction with DeviceN color spaces which describes the RIP's color management of /DeviceN color spaces.

NCDs are not used for particular colorants in some cases:

colorants that are directly rendered on the device, e.g. they wouldn't apply to Orange on a CMYKOG device.
colorants that are used by a NextDevice transform, see NextDevice named colorants.
colorants that are found in a SpectralData PDF object. N.B. If present, a SpectralData object contains one or more CxF/X-4 files embedded within the PDF file.

To be specific, if a PDF language job uses a color space array (CSA) such as:

[ /Separation (PANTONE 123 CVU) /DeviceCMYK {...} ]

the Harlequin named color management aims to replace both the alternate space (/DeviceCMYK in the example above), and the tint transform (the fourth element in the CSA which are usually quite lengthy), with those provided by an NCD that features (PANTONE 123 CVU).

Named color management is enabled with a PostScript language fragment:

CODE

<<
  /NamedColor [ /ncd_1 /ncd_2 ... ]
>> setinterceptcolorspace

which contains a list of named color database (NCD) PostScript language resource names. These NCD resources are commonly present as disk files in the SW/NamedColor directory, but may also be defined by OEMs using several methods detailed in this section. The definition of NCD resources is in Named color database resources.

In use, each NCD is searched in turn for the current colorant, e.g. (PANTONE 123 CVU). The first NCD that handles it is used to provide the replacements; the remainder of the NCD list is not searched. It is possible that the same colorants are included in more than one NCD in the list. The NCDs should be placed in precedence order.

There is no restriction on which, or how many, NCDs may be included in the list. Commonly, the list of NCDs might be a subset of those shipped with the RIP:

CODE

<<
  /NamedColor [
    /PantoneU /PantoneV /PantonePLUSCoated /PantonePLUSUncoated
    /PantoneCoated /PantoneUncoated /PantoneMatte
    /PantoneGoeCoated /PantoneGoeUncoated
  ]
>> setinterceptcolorspace

NamedColor databases for several generations of PANTONE colors are included with the Harlequin RIP and are shipped in the SW/NamedColor directory. Resource names are designed to be self-explanatory. Where data has been supplied by Pantone LLC using both M1 and M2 measurement modes the M1 data has the suffix _M1 on the resource file, and the resource with no suffix on its name is M2 data.

As an illustration of how searching works, this example illustrates the search for “ANTIQUE WHITE” through the IllustratorColors , PantoneCoated, and XRGB NCDs, which were chosen at random:

For many straightforward use cases, it is not necessary to write an NCD from scratch. Instead, it is convenient to make use of the HqnColorDatabase procset as described in HqnColorDatabase procset. This makes it simple to import named color data from spreadsheets and make use of standard methods. Details on this and other methods of constructing an NCD are in this section.

It is sometimes useful to use NamedColorOrder resources (especially the /Intercept NamedColorOrder resource) when providing the list of NCDs; see Named color order.

Following conversion to the alternate space of the NCD, the resulting colors may be further color managed. If the alternate space is a device space, this further color management may be controlled according to the rules of AllowColorManagement and ID; see Named color database resources. For examples of this control, see Merging component color pipelines and Illustrations of controlled merging of spots with color pipelines.