Re(6): embedded profiles in PDF/Postscript
Re(6): embedded profiles in PDF/Postscript
- Subject: Re(6): embedded profiles in PDF/Postscript
- From: Olaf Drümmer <email@hidden>
- Date: Sat, 5 Jun 2004 11:44:39 +0200
Dear Roger,
email@hidden wrote Fri, 4 Jun 2004 21:22:34 -0400
[...]
>
> If the PDF/X file only
>
> contains CMYK or Gray (without ICC profiles), the OutputIntent may simply
>
> point to a printing condition that is registered with the ICC registry,
>
> but it may (in addition or instead) contain a CMYK printer profile to
>
> describe the printing condition.
>
>
I am shocked to hear this, Olaf. I was under the impression, from my limited
>
PDF/X-1a reading, that the OutputIntent ICC profile MUST be embedded in the
>
PDF/X for complete compliance? What you say is that it is not mandatory. If
>
the user only puts in a reference to "some" printing condition that is
>
registered with the ICC registry, then this is opening the door to avoid
>
taking responsibility for the color in the document? People in America will
>
simply refer to CGATS TR-001 when in actuality the CMYK colors in the PDF/X
>
really does not have any relationship with CGATS TR-001. That's an
>
unfortunate shortcoming.
Well, whether you indicate the 'wrong' pointer to a printing condition or
whether you embed thw 'wrong' ICC profile leads to the same disaster.
What I find more important is that if the ICC profile is embedded in the
OutputIntent, this will make it much easier for tools and systems to make
use of it, e.g. for soft proofing on screen (like Acrobat 6.0
Professional can do).
>
> For PDF/X-3 (and for PDF/X-2) files that use device independent color
>
> (ICC based colors, Lab or CalGra and CalRGB), an ICC printer profile in
>
> the OutputIntent is mandatory.
>
>
OK for PDF/X-3 but we're not there yet. People still have not finished
>
digesting PDF/X-1a, let alone PDF/X, it seems.
Be aware though that if you wait for people to be ready, we'd still be
using XPress 3.3 or PageMaker 4 or FreeHand 3 for file exchange...
>
By the way, may I ask what CalRGB and CalGray are? Are these actual Adobe
>
ICC profiles? I think these are used in PDF 1.2 (Acrobat 4 files).
Think of it as a poor man's (and limited) colorimetric characterization
of grayscale and RGB color.
[...]
>
> For practical purposes it typically makes sense to always embed a printer
>
> profile in the OutputIntent,
>
>
Ah! Now, we're getting somewhere. It makes sense but it is not mandatory.
>
How prelavent, in your opinion, is the practice of embedding an OutputIntent
>
ICC profile in PDF/X-1a files? In Europe? In America?
Tools from callas software (pdfInspektor2, PDF/X-3 Inspector and
Preflight in Acrobat 6.0 Professional) always embed an ICC profile in the
OutputIntent. Acrobat Distiller will usually embed it. Indesign 3 will
always embed it. I believe that PDF/X CheckUp and PitStop offer both
(with and without embedding ICC profile). The Ghent PDF Work Group's
recommendations require you to embed the profile in the PDF/X
OutputIntent, but the settings they offer for download always embed a
SWOP profile (regardless of what the actual printing condition is).
>
> as a lot of tools and systems can pick it up
>
> and do useful things with it, like a proof simulation (or a starting
>
> point for a CMYK to CMYK conversion, if the file has to be printed in a
>
> different printing process, e.g. offset instead of gravure).
>
>
I agree 100% that it is a very responsible thing to do. Just like embedding
>
CMYK profiles in CMYK images. ;-)
The big advantage of an ICC profile in a PDF/X OutputIntent over regular
embedded ICC profiles is that unwanted conversions are easily avoided.
Maybe one day the ICC architecture will offer something like a "prepared
for" type of profile use: a CMYK profile is there (= associated with an
image or other objects) in the first place to let you know what printing
condition it refers to. Only if you explicitly request a conversion will
that conversion take place.
Olaf Druemmer
_______________________________________________
colorsync-users mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/colorsync-users
Do not post admin requests to the list. They will be ignored.