This is a < general > kind of question.
I'm at a point where I calculated the Bradford chromatic adaptation matrix,
to convert measured tristimulus values off my monitor to some "Destination"
Say my calibrated monitor white point XYZ = 76.06 80.27 87.13 (very close
to D65, I know, which was my calibration target).
My question is what Xn Yn Zn, then, do I use to convert to CIE Lab :
a) the chromatically-adapted monitor's white point, rescaled by the
monitor's white point Luminance (76.29 80.27 87.40);
b) the Destination white point (95.04 100.0 108.88)?
Some argue that, being so close to the target white point, I could skip
chromatic adaptation altogether.
To which I reply : I may not be so "fortunate" every time. And what if I
want to use the measurements in an ICC profile? Which is based on D50?
The issue I run into shows up when calculating Delta E for the measured
colors (red, green, blue, cyan, yellow, magenta and so on).
In one case, I get, say, an average of 9 Delta E (using rescaled monitor's
white point Luminance).
In the other case, using the Destination white point, I get, say, 16 Delta
I don't want to be "creative" with the results and use one that minimizes
I spent many days searching for an answer to what seems like a simple
question before posting here.
Hope someone can help,
/ Roger Breton
P.S. Graeme, I'm well aware of your position regarding the "true" monitor's
media white point as used in v2 profiles.