Re: math behind relcol intent
Re: math behind relcol intent
- Subject: Re: math behind relcol intent
- From: "Bruce J. Lindbloom" <email@hidden>
- Date: Sun, 13 Jan 2002 10:37:45 -0600
Daniel Lowicki wrote:
>
is someone maybe able to outline in short how the measurements are separated
>
into the tables for RelCol and the WP tag ? (simple subtraction ?)
>
>
And maybe how the AbsCol intent is then generated ? (addition ?)
It is not quite as simple as just adding or subtracting, but it's not much
worse than that. Chromatic adaptation is what's used to do the
transformation, and there are several different methods commonly employed
(von Kries, Bradford, XYZ scaling). If you're interested in the math, you
may find it in the ICC Profile Format Specification <
http://www.color.org>
in one of the appendices.
>
What I find especially interesting is that the IT8.72 Chart
>
for printer profilin doesn't even have a white patch
>
on it for measuring (at least I didn't find one).
The IT8.7/2 target is used for scanner profiling, not printer profiling. It
is the IT8.7/3 chart that is used for printer profiling, and that chart does
have a white patch.
--
Bruce J. Lindbloom
http://www.brucelindbloom.com