Re: White Point Editing
Re: White Point Editing
- Subject: Re: White Point Editing
- From: email@hidden (Bruce Fraser)
- Date: Fri, 30 Nov 2001 13:16:28 -0700
At 10:11 AM -0800 11/30/01, Steve Upton wrote:
At 11:29 AM -0500 11/30/01, Roberto Michelena wrote:
>> Please correct me if I am wrong, White Point Editing only makes
sense in the context of Absolute Colorimetric Rendering, right? It
will not have any effect on either Perceptual or Colorimetric
Rendering.
It can have an effect. In the other modes the colors are mapped
relative to the media white point.
I would say it shouldn't have an effect... The tables are computed and built
as relative during profile creation; after that, the wp should only be used
to bring them back to absolute when abscol rendering is requested. If relcol
is requested, they should be used as-is.
This is true and a good point...
Isn't that the idea?
However, it hasn't proved true for me in the past either... More than once
I've seen the wp tag influence the relcol rendering.
Different for each CMM, of course :(
This is what I have also seen at some times. I guess it remains a
bit of a mystery. I think you are probably right about the CMM
playing a role..
Guys, relative colorimetric maps the source white to the destination
white and tweaks all the other colors accordingly. So changing the
color of either white will change the results if the change is
applied to the other rendering intents. SOme profile editors are much
more specific about just what you're editing than others...
Bruce
--
email@hidden