Color Management for PDFs in Acrobat

Gustavo,

Firefox 3.0.1 does NOT need any plug-in whatsoever to enable color management.

You enable it in Preferences (accesible by typing about:config in the address bar).

You can then go to any number of sites that offer color mnagaement tests, such as

http://www.color.org/version4html.xalter

It works, very, very well,

Firefox is the ONLY color managed web browser that renders untagged images created in sRGB correctly (by assuming and assigning sRGB).

Safari, the other color managed web browser, unfortunately follows Apple's ghastly practice of assigning Monitor RGB to all untagged images. This has a catastrophic effect on untagged images saved in sRGB if one happens to be using a Wide Gamut monitor.

All Apple applications, from the Finder through Preview and iPhoto to Safari have this defect of throwing Monitor RGB at untagged images.

The problem is compounded by the fact that, currently, Flash transforms all tagged images into untagged ones. (Adobe has announced that help is coming with Flash.)

But Firefox's color management works beautifully.

Now that it comes, Firefox is (can be) colour managed with a plugin. But I wonder 'how much' colour managed is really that colour management.

Just wondering myself.

Yes, I never meant to imply that the issue was linked to the browser.

Just wondering whether Netscape is color managed or not. That's all.

Ramón,

color management for PDFs is established in Adobe Acrobat
and Adobe Reader (as we know now). This independent of the
browser.

Best regards --Gernot Hoffmann

Firefox 3.0.1 is fully color managed now, not by default, but it can easily be so configured. I don't know about Netscape.

Larry,

Preflight for Digital Color Press (for instance) contains
Output Intents. No need for the somewhat arbitrary
comparison with Acrobat 5.
As you're saying: the Output Intent is assigned as
AdobeRGB(1998), but this doesn't mean that the file
is embedded. I read in the help text that such a
profile is either embedded or mentioned by name,
then referring to a usually available profile at the
receiver.
Gustavo's method seems to show that the profile is
really embedded (header information is readable).

My doc consumes without Output Intent 1.915.627 bytes
and with OI 1.945.353 bytes. The difference is almost
30 kBytes. Not understandable, because the ICC profile
itself has about 0.5 kBytes.

I had to uninstall Adobe Reader, because my old browser
Netscape 7.1 couldn't be convinced to use Acrobat 7 by
default, despite assignments in Windows and Netscape
itself.

Thanks for the discussion and your help.

Best regards --Gernot Hoffmann

Gernot,

> 1. Is this Output Intent profile embedded ?

You can find out whether a profile is associated with the Output Intent by running preflight in Acrobat 7. Try Advanced/Preflight/Compatibility with Acrobat 5, for example. When done, look for Overview/Output Intents in the result panel. You should see aRGB there (for your rather interesting doc).

As to whether it is actually embedded in the pdf file will require some testing to confirm. Perhaps you can inspect the contents of two versions of the pdf with a text/binary editor (a variation of Gustavo's method) if logical deduction isn't good enough.

> Unfortunately, Reader 9 is now the default PDF interpreter, and I don't know how to define again Acrobat 7 as default.

Do you mean that Reader 9 launches instead of Acrobat 7 when you double click on a pdf file icon? If so, this should allow you to change it back:

http://kb.iu.edu/data/adhc.html

Regards, Larry

Gernot,

I believe PDFs store profiles 'outside' pictures, so they are assigned not really embedded.

But I may be quite wrong.

This
"no image has an assigned profile"
should have been
"no image has an embedded profile"
G.H.

Gustavo,

thanks for the investigation. Yes, no image has an
assigned profile, but I didn't know whether the
Output Profile was embedded.
It's a kind of PDF/X-1a style, but with RGB instead
of CMYK.

Meanwhile I followed Larry's recommendations and down-
loaded Adobe Reader 9.
The test shows (by appearance) that the Output Intent
is honoured, but Color Management settings are implicit.
No choice, opposed to Acrobat 7.

Unfortunately, Reader 9 is now the default PDF inter-
preter, and I don't know how to define again Acrobat 7
as default.

Best regards --Gernot Hoffmann