[Openicc] Questions about color pickers and graphics libraries under LINUX

[Chris Murphy]

Jan-Peter started this thread with some very interesting and  
important higher level questions with low-level implications.

A big problem for all operating systems is the divergence in display  
technologies rather than convergence. They are increasingly deviating  
from sRGB. And advancement in high quality display has been hindered  
by the rather aggressive LUTs in these displays needed to get them to  
simulate a CRT rather than their native behavior. This has been the  
source of various problems with gray-balance, cross-overs and  
posterization with many LCD displays.

Now there are affordable displays that have greater than 90%  
(whatever that means exactly) the gamut of Adobe RGB (1998), and  
several LED based displays are greater than this. There is a clear  
impact on all applications and the entire user interface as a result  
of using such displays.

While Apple makes claims about everything being color managed, this  
is in practice not true. It's still the case that Safari does not  
assume anything appropriate (such as sRGB) as source for untagged  
internet content, thus it assumes display RGB and that means  
everything looks much more saturated on these kinds of displays.

It's an old conversation that occurred maybe two or three years ago  
on this list, but after attempting to catch up I haven't found the  
issue of true system wide color management discussed. That is,  
everything untagged is assumed to be sRGB (or something and some day  
that something may change) and compensated for at an OS level, so  
that even applications that don't explicitly participate are in  
effect compelled to participate. They could only opt-out by expressly  
requesting it (i.e. no color management such as for games or  
performance reasons) or opt-in by specifying a source space other  
than sRGB.

This directly affects the ability of a system wide color picker to  
work correctly among various applications. This largely works in OS X  
now, but I can't say I'm impressed by its continued dependency on  
display RGB to make that work.

Chris Murphy


Chris Murphy
Color Remedies (TM)
New York, NY
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Co-author "Real World Color Management, 2nd Ed"