10:12 a.m.
Thanks
But while I'm using Perceptual there is a noticeable change in tone
values (the image becomes lighter on the monitor). I used to make color
and tone corrections i RGB mode only, so this lightening a little bit
scares me. In case of Relative Colorimetric there is no change.
10:34 a.m.
Hallo I have followed this talk, and I have seen that it gets lighter
on screen and lower in areas very dark (total ink)
Karsten
Den 22/6-2004, kl. 10.12, skrev Borislav Ivanov:
Thanks
But while I'm using Perceptual there is a noticeable change in tone
values (the image becomes lighter on the monitor). I used to make
color and tone corrections i RGB mode only, so this lightening a
little bit scares me. In case of Relative Colorimetric there is no
change.
_______________________________________________
ECI-EN mailing list
ECI-EN(a)lists.transmedia.de
http://lists.transmedia.de/mailman/listinfo/eci-en
6:11 p.m.
That is often the case with Perceptual intent. It tries to maintain
some of the tonal separation that exists outside the gamut by scaling
the whole gamut "inward." This means the in-gamut colors have to be
desaturated a bit. With Relative Colorimetric, all of the out-of-gamut
colors are mapped onto the gamut boundary, which effectively swallows
any detail information in those colors. The in-gamut colors pretty much
stay put, so you don't get that desaturation effect.
Regards,
Mike Cummings
CHROMiX Technical Support
1-866-CHROMiX (247-6649)
cummings(a)chromix.com
On Jun 22, 2004, at 1:12 AM, Borislav Ivanov wrote:
Thanks
But while I'm using Perceptual there is a noticeable change in tone
values (the image becomes lighter on the monitor). I used to make
color and tone corrections i RGB mode only, so this lightening a
little bit scares me. In case of Relative Colorimetric there is no
change.
_______________________________________________
ECI-EN mailing list
ECI-EN(a)lists.transmedia.de
http://lists.transmedia.de/mailman/listinfo/eci-en
6:40 p.m.
Am 22.06.2004 um 18:11 schrieb Mike Cummings:
That is often the case with Perceptual intent. It
tries to maintain
some of the tonal separation that exists outside the gamut by scaling
the whole gamut "inward." This means the in-gamut colors have to be
desaturated a bit. With Relative Colorimetric, all of the out-of-gamut
colors are mapped onto the gamut boundary, which effectively swallows
any detail information in those colors.
Roughly, mapping colors onto the gamut boundary normally preserves
L-Values which often preserves differentiation (You might imagine an
LAB-image completely desaturated (which will appear gray) - all that
happend was moving all colors towards L-axis. Of course you will lose
color but not necessarily any detail.) In addition, most profile-making
programs add some 'perceptual treatment' to out-of-gamut-colors within
colorimetric intent - instead of simply moving linearly onto the gamut
boundary.
Regards, Andre Schuetzenhofer
The in-gamut colors pretty much stay put, so you
don't get that
desaturation effect.
Regards,
Mike Cummings
CHROMiX Technical Support
1-866-CHROMiX (247-6649)
cummings(a)chromix.com
On Jun 22, 2004, at 1:12 AM, Borislav Ivanov wrote:
Thanks
But while I'm using Perceptual there is a noticeable change in tone
values (the image becomes lighter on the monitor). I used to make
color and tone corrections i RGB mode only, so this lightening a
little bit scares me. In case of Relative Colorimetric there is no
change.
_______________________________________________
ECI-EN mailing list
ECI-EN(a)lists.transmedia.de
http://lists.transmedia.de/mailman/listinfo/eci-en
_______________________________________________
ECI-EN mailing list
ECI-EN(a)lists.transmedia.de
http://lists.transmedia.de/mailman/listinfo/eci-en
6:55 p.m.
On Jun 22, 2004, at 9:40 AM, Andre Schützenhofer wrote:
Roughly, mapping colors onto the gamut boundary
normally preserves
L-Values which often preserves differentiation (You might imagine an
LAB-image completely desaturated (which will appear gray) - all that
happend was moving all colors towards L-axis. Of course you will lose
color but not necessarily any detail.) In addition, most
profile-making programs add some 'perceptual treatment' to
out-of-gamut-colors within colorimetric intent - instead of simply
moving linearly onto the gamut boundary.
Yes, my explanation was a rough description. If you graph the effects
of different rendering intents with ColorThink, for example, you can
see this. The whole gamut is affected in every intent, and the line
between Perceptual and Rel Col is more blurry than one would think. But
to a first approximation, the effects are in accord with the simplified
scheme of Perceptual = in-gamut scaling and Rel Col = in-gamut
unaffected, out-of-gamut pulled into gamut boundary.
It's interesting to graph similar profiles made with different vendors'
software. You can clearly see that there is no single method of
implementing a rendering intent.
Regards,
Mike Cummings
CHROMiX Technical Support
1-866-CHROMiX (247-6649)
cummings(a)chromix.com
7257
days inactive
7257
days old
eci-en@lists.callassoftware.com
4 comments
4 participants
participants (4)
-
Andre Schützenhofer -
Borislav Ivanov -
Karsten Petersen -
Mike Cummings