Decoding ColorSync monitor profiles
Decoding ColorSync monitor profiles
- Subject: Decoding ColorSync monitor profiles
- From: Roger Breton via colorsync-users <email@hidden>
- Date: Fri, 22 Nov 2019 21:32:42 -0500
I'm in the ColorSync Utility, on a MacBook Air, looking at the "Phosphor"
tab (French MacOS 10.12.6) of the "Color LCD-77E200AD-B0E6..icc" profile.
I'm intrigued by the displayed Red, Green, Blue and White chromaticities:
x y
------ -------- ---------
Red 0.5881 0.3333
Green 0.3229 0.5495
Blue 0.1542 0.0900
White 0.3127 0.3290
White chromaticities are easy to decode, this is straight Rec 709 HDTV D65.
However, the red, green and blue chromaticities are not straight Rec 709.
As you know, these chromaticities are incomplete without the Y = Luminance
factor.
Is there a way, mathematically, to compute the Y from the x and y?
I'm using Robin Myers's excellent ColorConverter 2.2 to "guestimate" the Y
by typing in the x and y values, and trial-and-error different Y factors,
until I hit the "maximum" a* and b* for that color, to get at a "realistic"
CIE Lab value.
Please forgive my technical ignorance.
For the red primary, I get the "max" a* with a Y = 55 value which gives a
CIE Lab value of 79.04 90.28 54.12. Somehow, this "method" of mine does not
make sense? I get a Chroma of 105 and a Hue angle of 31 degrees.
Any help is appreciated.
/ Roger Breton
_______________________________________________
Do not post admin requests to the list. They will be ignored.
colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden