re: posterization in ICC profile
re: posterization in ICC profile
- Subject: re: posterization in ICC profile
- From: Dan Reid <email@hidden>
- Date: Thu, 14 Feb 2002 13:50:59 -0700
On Wed, 13 Feb 2002 17:58:54 -0500, email@hidden wrote:
>
We have two devices running the same target profile (a profile of our
>
primary newspaper's press) and we're having problems getting the two to
>
"match". On the smaller device (a Canon 8500) we get some posterization in
>
the highlights and the blacks seem hollowed out. The color is very close to
>
our IRIS 2PRINT but the dissimilarities are too annoying to live with. The
>
profile was created outputting 1440 color patches and I was wondering if
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maybe that was too much information. Would creating the ICC profile by
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outputting, say 800 patches maybe make an improvement? My gut tells me the
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proofer profile is forcing the printer to do something wacky, giving me a
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posterized proof. Is this a black generation thing? At the moment I
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specified (in ColorBlind) a Total ink of 270, max K is 90, K weight is 7, K
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start is 5, and colro GCR is 50.
First off you probably don't need to use 1440 patches for the Canon even 800
is probably too much as the device is not *wacky*. The problems you are
experiencing are purely separation issues. Try using a K=100 and a UCR
separation instead and see if the shadows get a little richer. Have you
viewed a 3D model of the Canon profile? That would tell you a lot about how
shadow regions are being characterized. UCR may also help with the
posterization issues too.
--
Dan B. Reid
RENAISSANCE PHOTOGRAPHIC IMAGING
Color Imaging Solutions Provider
http://www.rpimaging.com | email@hidden
Toll Free: (866) RGB-CMYK [ 866-742-2695 ]
Local: (505) 471-4126
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