(v13) CMM hints

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

As from Harlequin 12.1r2 the alternate CMM array may optionally include a fifth item; a dictionary containing additional configuration items or ‘hints’ to the CMM interface.

[ /CMM <name> <input-color-space> <output-color-space> <hints> ]

CMYKPassThrough

From Harlequin v12.1r2 the (optional) CMYKPassThrough is defined. This hint should be set to true if you know that the selected transform will deliver all color values unchanged if the input color values are zero for all non-CMYK colors; in other words, no changes will be made to either CMYK or to other color values in that case. Setting to true will allow the RIP to avoid some processing steps and therefore increase throughput. It should only be set to true if you are confident that the CMM will behave in this way.

[ /CMM (ECE) /DeviceCMYK /DeviceCMYK <</CMYKPassThrough true>> ]

IndependentSpots

From Harlequin v13.0r0 an additional, optional, IndependentSpots parameter is defined. It is intended to be used to identify spot colors that are transformed independently of all other process or spot colors in the custom color space. In alternate CMMs that has been found to apply to White and its aliases and to varnishes. Each of the colors identified may be transformed by the CMM, but only if that transform is unaffected by other colorants. If a second spot name in the job maps onto the same device colorant as an independent spot, then it, too, may be identified as an independent spot.

Marking spots as independent allows the RIP to avoid a lot of the work in managing overprinting in particular, increasing speed. This will help most often with white underprints and varnish overprints, where best practice is to paint them on top of the Z-order and set to overprint in the PDF.

All spot names used must also be present in SeparationColorNames; they may be omitted from SeparationOrder if they’re not device colorants.

The value of IndependentSpots should be an array of spot names, as strings or name objects such as:

<<

...

/SeparationColorNames [(Cyan) (Magenta) (Yellow) (Black) (White) (Weiss)]

/SeparationOrder [(Cyan) (Magenta) (Yellow) (Black) (White)]

...

>> setpagedevice

<<

...

/NextDevice <<

/InputColorSpace [

/CMM (MyAlternateCMM) [

/DeviceN

[(Cyan) (Magenta) (Yellow) (Black) (PANTONE Reflex Blue) (Forest Green) (White) (Weiss)]

/DeviceCMYK {pop pop pop pop}

]

[

/DeviceN

[(Cyan) (Magenta) (Yellow) (Black) (White)]

/DeviceCMYK {pop}

]

<<

/CMYKPassThrough true

/IndependentSpots [/White (Weiss)]

>>

]

>>

...

>> setreproduction