[Openicc] Ghostscript CMS [was: PDF frustration]

[Michael Vrhel]

Gerhard and Kai-Uwe,

Thanks for the comments on having proofing capability built into the
ghostscript color management.  I do appreciate the need to mush all these
things together at one time as well as the obvious (but overlooked by me!)
problem with the output being possibly halftoned. Proofing is critical to a
huge number of users. I need to think about this a bit more but it is very
likely that I will be adding a "Proofing" profile to the design.

Kind Regards,

Michael








> -----Original Message-----
> From: Gerhard Fuernkranz [mailto:nospam456 at gmx.de]
> Sent: Monday, December 01, 2008 12:54 PM
> To: michael.vrhel at artifex.com
> Cc: 'Kai-Uwe Behrmann'; 'Ralph Giles'; 'OpenICC Liste'
> Subject: Re: [Openicc] Ghostscript CMS [was: PDF frustration]
> 
> Michael Vrhel wrote:
> > You bring up an excellent comment with respect to proofing and effects.
> My inclination is not to get the proofing profile tangled up in
> Ghostscript. If someone really wants to use one, then the proofing
> application should really make that adjustment after ghostscript has
> created the result for the destination profile. That said, I am open to
> hear arguments to the contrary.
> 
> Michael,
> 
> IMO one contrary argument is that a subsequent color conversion is very
> hard to accomplish if not impossible once gs has rasterized the page to
> a bi-level image (in those cases where the halftoning is already done by
> gs and not by a subsequent backend - and I guess you don't plan to
> discontinue gs' halftoning functionality).
> 
> On the other hand it is IMO theoretically possibly to create a let me
> call it "proofing output profile", whose B2A tables combine the
> transformations PCS -> emulated printer color space (-> PCS) -> actual
> printer color space. Proofing could then be easily enabled by supplying
> such a profile to gs as output profile, w/o need that gs must be aware
> of proofing. I just don't know a readily available tool for building
> such a profile [to a limited extend this can be accomplished in two
> steps with help of the lcms icclink utility, using the -x option].
> 
> Regards,
> Gerhard