[Openicc] Open Source compatible AdobeRGB profile

[almccart at lexmark.com]

I suspected using that term would get me in trouble :-)

It is probably better to think of these profiles as 'profiles that refer 
to 
standard color spaces'  -- NOT standard profiles.

When I used the term "standard" profiles I meant profiles that pertain to 
standard 
color encodings.
E.g., sRGB is a particular standard RGB encoding spec'd in IEC 61966-2-1. 
A profile built to color convert that color encoding to/from ICC PCS  + 
that also
adheres to the ICC profile specification - can be loosely called a 
"standard profile"
but is still better thought of as a profile FOR a standard color space. 

The ICC is working on posting some such profiles for the common RGB color
spaces and the CMYK color spaces that are defined in the ISO printing 
standards. 
The Adobe RGB profile is there now. [Perhaps open source systems can avoid
distribution licensing problems by not bundling the Adobe RGB profile but 
rather
referring users to that website.]     www.eci.org has some of such 
profiles as well.

So the short answer is - a color space encoding is determined to be 
standard when
it is specified in an ISO or IEC standard, or is in wide use in public 
domain [Adobe RGB].
Then a profile that is correctly built for that color space - can loosely be called a 
standard profile. 

Complicating caveat: note that profiles contain more than one color 
conversion path. 
The two major paths in all ICC profiles are 'perceptual rendering' and 
'colorimetric 
conversion'.  Any profile that contains a CLUT structure element in the 
perceptual 
rendering path will have proprietary behavior in that path. So those 
profiles give 
standard behavior only when used in a color matching - colorimetric 
conversion 
operation. 

Best regards,
Ann McCarthy
Lexmark CPD
Imaging Systems Engineering

"To every complex problem there is a simple solution - and inevitably it 
is wrong"   HL Mencken




Sven Neumann <sven at gimp.org>
07/06/2006 06:18 PM

 
        To:     almccart at lexmark.com
        cc:     Hubert Figuiere <hfiguiere at teaser.fr>, OpenICC Liste 
<openicc at lists.freedesktop.org>, openicc-bounces at lists.freedesktop.org
        Subject:        Re: [Openicc] Open Source compatible AdobeRGB profile


Hi,

On Thu, 2006-07-06 at 17:02 -0400, almccart at lexmark.com wrote:

> b. Provide for retrieval of standard profiles [actual std and defacto
> std] to be used when content files 
> use the color space label approach. [e.g., profiles provided through
> links on the ICC website: www.color.org]

Who defines what a standard profile is and what label to use for it?

> My apologies if this is review for most of you.  It seemed from some
> comments that a background 
> statement might be helpful. 
> 
Thanks for the summary.


Sven




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