Message
Re: [colorvision_group] Re: Profiling without calibration and monitor matching (newbie questions)
2008-02-14 by CDTobie@aol.com
In a message dated 2/14/08 2:42:11 PM, yahoo@... writes:
However, you *can* do it in the CMS before the 8 bits per
channel are put in the frame buffer, which ought to be
performing the colour transformations specified by the
(display) profile in, I hope, more than 8 bits of accuracy,
given that it's being fed 16 bits per channel by Photoshop.
If the CMS and/or profile are really only working in 8 bits
per channel, I'm underwhelmed and surprised. (It's true that
this would be a moot point if I only had 8 bits per channel
in the image colour space. I never do: I'm far too keen on
sorting out the exposure after the event, and always shoot
raw; even with JPEG, I'd still work with 16bpp as an
intermediate step.)
Calcs can be done in a larger space, but when all is said and done, you are sending 8 bits per channel to the videocard, and from there to the display. No highbit pipeline yet. However, some printer export modules and RIPs offer a highbit pipeline, and I don't find it to improve prints, so I'm not hanging my hopes on magic from a highbit pipeline to displays (if and when it comes). But its great for corrections, even if the actual pipeline is only 8 bits/channel. Thats why loading the same LUT tables to the display, instead of the videocard, can smooth the visible result onscreen, to some degree. But only if you are asking for fairly radical corrections in the LUT, like shifting the entire gamma significantly... and its only an on-screen thing, it doesn't effect the files, or the prints, just the screen preview.
C. David Tobie
WW Product Technology Manager
Digital Imaging & Home Theater
Datacolor
CDTobie@datacolor.com
www.datacolor.com/Spyder3
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