Re: Question about input devices and Icc profiles...
Re: Question about input devices and Icc profiles...
- Subject: Re: Question about input devices and Icc profiles...
- From: Roger Breton <email@hidden>
- Date: Tue, 13 Jul 2004 08:51:59 -0400
>
I was thinking about the Input profiles and this is my conclusion...
>
With the right profile ALL the input devices has exactly the same gamut! =
>
and this gamut could be the cieLab space...
You are correct in that ALL profiles have to encode the CIE Lab space on the
input side.
>
and let me explain please...
>
All the devices (scaners, digital cameras etc...) capture RGB values =
>
(normally 8 bit by channel) from 0 to 255 for each color.
In 8 bit, yes.
>
And when you make the Icc the Soft is making a relation between the =
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"Spectral" colors of the target and RGB answer of the device...
A relation between the "colorimetric" measurements of the target and the RGB
answer of the device. True.
>
this =
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means that all the spectral color are "scaneable"... them, for each =
No, that is not true. The target does not sample the whole CIE Lab space.
Rather, it samples the whole photographic process color space. Kodak or Agfa
or Fuji papers are not able to reproduce the whole CIE Lab space but only a
very small portion of it. The same as a press or an inkjet printer. Very
small fraction, indeed. Which makes some say that the CIE Lab encoding is
very inefficient.
>
color of the Lab space, you should to have an RGB value.... I dont care =
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if you got the same RGB for a different Lab-s (you got 6451600 possible =
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Lab values against 16581375 RGB values)....=20
NO, that is not how I understand this system works. See above.
>
I dont know if you know what I mean (sorry my poor English)... but is =
>
that right????
No, for the reasons I exposed above.
Roger Breton | Laval, Canada | email@hidden
http://pages.infinit.net/graxx
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