The All colorant in DeviceN spaces

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

The use of the All colorant in /DeviceN spaces is not allowed in the [RB3] or [PDF1.6] specifications, which says an error should be thrown. In the RIP, if any of the colorants named in a /DeviceN color space are All, the RIP ignores the colorant list and uses the tint transform. That is, the standard tint transform provided by the job is used, named color management is not used to replace the alternate space or tint transform.

This can be useful when intercepting device spaces for special effects such as lightening /DeviceCMYK colors to 50% of the original values, for example:

CODE

<<
  /DeviceCMYK [ /DeviceN
                [/All /All /All /All]
                /DeviceCMYK {4 {0.5 mul 4 1 roll} repeat}
              ]
>> setinterceptcolorspace

Another example:

CODE

<<
  /DeviceCMYK [ /DeviceN
                [/All /All /All /All]
                [ /DeviceN [/Spot1 /Spot2 /Spot3 /Spot4] /DeviceCMYK {} ]
                {{4 {0.5 mul 4 1 roll} repeat} % Reduce all 4 values by 50%
              ]
>> setinterceptcolorspace

This is a way of modifying CMYK values and passing them to the inner /DeviceN space. In this case the color values seen by the /DeviceN are lightened to 50% of the original /DeviceCMYK values. The set of spots may be device colorants. Otherwise, the modified color values is passed to the inner tint transform, in this case passed directly to /DeviceCMYK. Named color management using NCDs are ignored for these spots because NCDs are not applied to nested /DeviceN spaces.