Monitor calibration and color managed workflow question

On 20 Dec 2005 15:15:48 -0800, "Bill Hilton"
wrote:

Loren wrote ...

Am I correct that this "matrix file" is what gets loaded to the
lookup table registers on the graphics card?

Graeme answered that well ...

Indeed! I finally understand the difference.

My thinking here is largely based on my experience with an older
notebook where the backlight has gone seriously "warm", to the point
where color errors are obvious. I wasn't able to fix this with Adobe
Gamma ... I still don't understand what happened to Adobe Gamma,
though. It didn't appear to be able to do anything to help my problem,
color managed app or not.

Adobe Gamma does a very poor job with LCDs and laptops ... I thought
this was mentioned in the documentation. Even the original Spyder does
poorly with laptops ... if you're trying to do color-critical work on a
laptop you need to spend $200 or so and get the Eye-One or the Sypder 2
or the Monaco (Optix?) ...

I've seen that warning several places, and I'm not trying to do
critical work. Just trying to avoid being grossly offended during
everyday surfing... Adobe Gamma had worked well enough when the
problem first began appearing, but then seemed to stop doing anything
at all. WiziWYG fixed the worst of the problem satisfactorily - and
could take the colors past there to wild extremes if I wanted it to.

Loren

"Graeme Cogger" wrote in message
....
Instead of independent RGB curves, a monitor profile
uses a 3D table ...

This is not really the case. Monitor profiles are usually matrix based, and
define three curves, one per gun, and not a 3d lookup table.

Adobe RGB, and the other popular working spaces are also matrix based, so
there is generally no 3d lut in play for display of an image.

OTOH, Scanners and printers are more complex beasts, and generally do
require use of the full 3d look up table for good color.
--

Mike Russell
www.curvemeister.com

In article , RE-
E-MOVE says...
"Graeme Cogger" wrote in message
...
Instead of independent RGB curves, a monitor profile
uses a 3D table ...

This is not really the case. Monitor profiles are usually matrix based, and
define three curves, one per gun, and not a 3d lookup table.

Adobe RGB, and the other popular working spaces are also matrix based, so
there is generally no 3d lut in play for display of an image.

OTOH, Scanners and printers are more complex beasts, and generally do
require use of the full 3d look up table for good color.


Well that shows how little I know I just checked some monitor
profiles and you're correct - they're not based on LUTs. I'd always
thought that was the norm, not the exception.

Oh well - the other point still stands, and I believe that the
adaptation for the xyz co-ordinates is also not achievable via a
graphics card LUT. I guess the point is that certain corrections must
be made via th profile, and not the graphics card.

From: "Graeme Cogger"
....
Oh well - the other point still stands, and I believe that the
adaptation for the xyz co-ordinates is also not achievable via a
graphics card LUT. I guess the point is that certain corrections must
be made via th profile, and not the graphics card.

Matrix profiles have RGB definitions that are in xyz.

Your main point, which is that a good monitor profile alone is not enough to
produce a correct output of a tagged image on a monitor, is correct.
---
Mike Russell
www.curvemeister.com