Intercepting device spaces

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

The setinterceptcolorspace operator is used to replace untagged device spaces. ICC color management has many examples of using ICCBased color spaces as the intercept space. As well as ICCBased, any valid PostScript language or PDF color space is allowed as the intercept color space, with the exceptions of Indexed and Pattern. This includes the use of Harlequin extension color spaces such as CMM custom color spaces, Alternate CMMs: CMM custom color spaces.

This is an example of intercepting /DeviceCMYK with four spot colors:

CODE

<<
  /DeviceCMYK [/DeviceN [/Spot1 /Spot2 /Spot3 /Spot4] /DeviceCMYK {}]
>> setinterceptcolorspace

It might be used where an application has exported the PostScript language using standard device spaces for convenience, but intended to be used with spot colorants on the press. The workflow passes spot color values to the output device if they are renderable. Otherwise, they are handled as described in DeviceN color spaces.

The /DeviceRGB and /DeviceGray intercepts may also be intercepted with /DeviceN spaces. If so, the RIP internally inverts the sense of color values in the range of 0-1 because /DeviceN is a subtractive space, while these intercept spaces are additive.

If the intercept is a /DeviceN space, in most use cases all colorants in the colorant list is renderable on the device. If the colorants are not renderable, the RIP attempts to use the alternate space and tint transform as normal for /DeviceN spaces. There are restrictions on the tint transform for the /DeviceRGB and /DeviceCMYK intercepts; they must conform to one of these two cases, or the job will abort with an error:

The tint transform may be compatible with the PostScript Calculator function as defined in the [PDF1.6] specification. The RIP also allows the additional PostScript operators, "exec", "for", and "repeat".
The tint transform may be the illegal tint transform: “{ null }”, which is treated specially by the RIP. This is for the case where the tint transform should not be executed, and therefore it is not necessary to specify a valid tint transform. If an attempt is made to execute the illegal tint transform, the job aborts with an error.

In HHR/HMR v12 from v12.0r1: Using a /DeviceN color space as an intercept space in conjunction with the use of NextDevice transforms isn't supported. Their use isn't prohibited, but the NextDevice transform may or may not be applied depending on other factors in the configuration and the job.