[gs-devel] CM in GS

Michael Vrhel michael.vrhel at artifex.com
Tue Aug 5 23:10:03 PDT 2008


Hi Kai-Uwe,

We are in the process of a major rework of the ICC color management.  The
new design will result in expanded support as well as significant
flexibility.  In particular it will be possible to use a CMS of your choice
(e.g. littleCMS or your own custom engine) as well as easily specify a
device output profile (e.g. the cupsICCProfile if desired).  

Today, if you want to use a specific output profile for your device, you
need to convert the profile to a CRD (color rendering dictionary).  See the
littleCMS tool icc2ps to perform this operation.  You will need to select a
single rendering intent at the time of the conversion, since a CRD describes
only a single rendering intent.  In a command line situation, the CRD would
precede the PDF file to be processed.  

For example 

gs -sDEVICE=tiff32nc -o MyOutputFile.tiff -f myCMYKCRD.ps FileToProcess.pdf

In the current code, the perceptual rendering intent is used with all the
source ICC profiles.   This will change in the future, and the rendering
intent specified in the PDF file will be provided to the CMS, along with the
actual object type (e.g. vector, text, or image).  At compile time, the CMS
can be set up to use this information in what ever manner is desired.
 
I hope this answers your questions.

Kind Regards,

Michael Vrhel







 





> -----Original Message-----
> From: gs-devel-bounces at ghostscript.com [mailto:gs-devel-
> bounces at ghostscript.com] On Behalf Of Kai-Uwe Behrmann
> Sent: Monday, August 04, 2008 11:22 AM
> To: gs-devel at ghostscript.com
> Subject: [gs-devel] CM in GS
> 
> Hello,
> 
> assuming that Ghostscript provides a pdftoraster filter for CUPS, does it
> support the cupsICCProfile output profile?
> 
> A additional question arrised about the colour convertion rendering
> intent. How is this determined? By the PDF document itself? Is it hard
> coded into the filter? ...?
> 
> 
> thanks for any insights,
> Kai-Uwe Behrmann
> --
> developing for colour management
> www.behrmann.name + www.oyranos.org
> 
> _______________________________________________
> gs-devel mailing list
> gs-devel at ghostscript.com
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