Re: Creating ICCs with pigmented inks
Re: Creating ICCs with pigmented inks
- Subject: Re: Creating ICCs with pigmented inks
- From: Graeme Gill <email@hidden>
- Date: Fri, 12 Jul 2002 11:51:53 +1000
Dan Reid wrote:
>
If I remember correctly, and maybe I am not, there is viewing tag available
>
in the ICC spec to indicate what the viewing conditions are. Now I don't
>
know of any product that uses this tag but I believe it does exist in the
>
ICC spec. How it would be used is beyond me.
Yes, there are tags to hold various sorts of viewing information.
There are problems with this though. One is that there aren't
the right tags to define the viewing conditions needed for
something like the CIECAM97 color appearance model.
Another is that there is considerable confusion in the ICC
spec. in regard to whether such viewing conditions information
represents the conditions under which the profile is valid,
or whether it represents the viewing conditions that
the device was measured under, and have been transformed
from (using an unspecified CAM), to the standard ICC viewing
condition equivalent. Sections of the spec. make it seem
like the latter is what should be done. It is unclear
whether this should be the case for just some, or all
of the intents. If CMM's actually did this, it would
be impossible to recover the original calorimetric data
for a device from a profile.
In practice, I get the impression that no CMMs do this
color appearance transform in creating a profile (certainly
mine doesn't).
>
Logo ColorLab is an unsupported, no documentation, you're on your own color
>
utility application. If you know what you are doing it can do some really
>
nifty things aside from using different illuminants in colormetric
>
calculations. Again spectral measurement data is required to compute
>
colormetric data with a different illuminant than D50.
Sounds about as hard to use for the typical user as Argyll :-)
Graeme Gill.
_______________________________________________
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.