Re: colorsync-users digest, Vol 2 #112 - 15 msgs
Re: colorsync-users digest, Vol 2 #112 - 15 msgs
- Subject: Re: colorsync-users digest, Vol 2 #112 - 15 msgs
- From: joe borne <email@hidden>
- Date: Fri, 29 Dec 2000 19:13:41 -0500
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Could someone help me out with some basic color science terminology.
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When I see someone post "within 2 Delta" what does this mean?
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What are the variables in measuring color in color management?
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Delta E? L?
Well, to respond directly to the two, here is how it goes in layman's terms:
A "Delta-E" is a unit of measurement that represents one degree of visual
difference. Essentially, as soon as a color changes enough that the average
person can tell the difference, that much change equals a Delta-E.
Now as far as "L" is concerned, the only place I see the term applied is
when referring to the lightness pole in the 3-dimensional color space model
of Lab. The L pole stands straight up, with the lightest colors at the top
and the darkest at the bottom. The a and b poles transect it horizontally
giving you a shape like the gyroscopes we all had as kids. The "a" and "b"
poles represent green/red and yellow/blue respectively. So on one end of the
"a" pole is red and the other end green (it is this way because you never
see a reddish green or a blue-ish yellow). The "b" pole follows suit by
doing the same with blue/yellow. This model enables you to plot almost any
color within a 3-dimensional space, therefore giving it a definable value.
Hope that helps. If you want a good book to get you up to speed on the
basics, I recommend the GATF guide to color management (www.gatf.org).
--
Joe Borne
Color & Graphic Technology Consultant
(859) 282-0393
-- "The opinions expressed by this individual do not necessarily reflect the
actual opinions of this individual. Unless you agree with these opinions, in
which case I will feel free to spread the blame around when people get mad
at me." --