On Jun 3, 2005, at 11:48 AM, Paul Sherfield wrote:
Hi all
I have just caught up with the RI discussions, very interesting and
Chris's
comments match my own 'Real World' findings!
Having put together a number of colour managed page work flows
processing
1000's of RGB images to CMYK a month, the CM needs to be automated.
After a lot of testing I can confirm that for 95% of RGB images the
relative
colorimetric intent, with BPC, is the most suitable. The remaining 5%
are
not 'spoilt by this intent, just not as good as using perceptual.
Yeah and what this means for developers making products that produce
output device profiles, we really need well behaved colorimetric
intents! It's not good enough to just focus on the in-gamut colors and
maybe some out-of-gamut colors.
To test for this, build a Granger Rainbow (or download it from
colorremedies.com/realworldcolor and click on Downloads), assign an RGB
profile to it and then convert using an output profile you wish to
test. I don't expect RC to do a perfectly smooth job, especially when
using a wide gamut color space as source. But for it to posterize and
have nasty holes in it, not OK. This is not an irregular occurrence and
causes a greater dependence on perceptual rendering than is otherwise
necessary.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
---------------------------------------------------------
Co-author "Real World Color Management, 2nd Ed"
Published by PeachPit Press (ISBN 0-321-26722-2)