Colormanagement inconsistencies in Adobe CSx [was: Linked images changing color values in Illustrator]
Colormanagement inconsistencies in Adobe CSx [was: Linked images changing color values in Illustrator]
- Subject: Colormanagement inconsistencies in Adobe CSx [was: Linked images changing color values in Illustrator]
- From: Klaus Karcher <email@hidden>
- Date: Fri, 09 Nov 2007 12:28:30 +0100
Steve Lehning wrote:
We are using Adobe CS3.
We have had some projects that have almost gone sour
because of images that seem to be doing some
conversion in Illustrator.
Klaus Karcher wrote:
I encountered a similar problem in AI CS2 (also affects AI CS3): in some
situations, Illustrator converts CMYK images without further inquiry
even when the embedded profile matches the working space.
After a good deal of trials, I finally found the reason: there are two
versions of the profile "ISOcoated_v2_eci.icc" (very popular in Europe),
both are from <http://eci.org/>, one (created in January 2007) is a ICC
v 2.0.0 profile and has only an ASCII description tag and the second
(created in February 2007) is a ICC v 2.4.0 profile with an ASCII,
Unicode and Macintosh name. Everything else is identical.
If Illustrator's Color settings file contains a different version of the
Profile than the image you import, it will be *converted without any
warning* even if Illustrator is set up to keep CMYK numbers an warn
about mismatches.
If someone wants to verify/confirm the bug: here are some test files
<http://digitalproof.info/AI-CS2/ASCII_und_Unicode.zip>
Please, Adobe: *This is a serious, hard to track bug which should be
fixed ASAP IMHO*
For the sake of completeness: as yet I encountered several
inconsistencies concerning profiles that only differ in version in CS2
an CS3:
- InDesign seems to behave consistent in itself: if one places an image
with the same profile version than the working space and a second one
with a different version, there are no warnings and no conversions. If
you export a PDF with embedded source profiles, both images get the same
profile (the working space version). It's not correct to replace the
source profile IMO, but at least it avoids further confusion in Acrobat
or RIPs.
- Photoshop assumes that there are no differences between the profiles
if you duplicate a Layer from one image to the other, but it assumes
different profiles if one explicit converts an image from one to the
other (i.e. the conversion takes place).
Please note: to allow a conversion when the user asks for it is what I
assume as correct behavior, regardless whether the profiles are
different or not. To omit conversions specifically requested by the user
without notification when Photoshop assumes a "null conversion" is the
(longstanding) bug IMO: There are good reasons to convert from CMYK to
CMYK with output profile = input profile.
- Illustrator's behavior is the most dangerous: It forgets to warn the
user about the "mismatches" and converts unauthorized.
- Acrobat assumes the profiles are different. E.g. if it encounters a
source profile with a different version than the output intent, the
output preview shows converted values. Thats consistent in itself but
inconsistent e.g. with InDesign's behavior.
That's it so far.
I'd be pleased to hear from one of the Adobe staff whether my
annotations were received or whether I have to submit an "official" bug
report.
TIA,
Klaus Karcher
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