Dan Margulis Applied
Color Theory
Color Management Workflows
Date: Wed, 26 Feb 2003 17:09:09 -0500
From: "tbrain"
Subject: Color Management Workflows
I just finished REAL WORLD COLOR MANAGEMENT, and it has
been very insightful. I am struggling to learn how to piece together my own
color management "workflow" as well as how to make suggestions
for clients who have expressed an interest.
I thought I had a good handle on SOURCE and DESTINATION
profiles, but depending on the workflow choice below, I'm not entirely sure
I'd know which profiles to use, particularly when it comes to tagging
images and when to drop the embedded profile and reassign a new one.
Anyway, I've attempted to summarize the various color
management workflows. I encourage feedback, clarification, and answers to
the few questions I've added:
When implementing color management, there are several
workflows in a print environment. Here are the major ones from which to
choose (realizing some shops may choose a hybrid):
*** Scanner-Based Color Management: images are
converted to CMYK during the scanning phase, using the scanner's profile
for SOURCE and a proofer/press for DESTINATION.
*** Photoshop Color Management: digital photos or
scanned images are converted to CMYK within Photoshop (or equivalent). The
digital camera or scanner is the SOURCE profile and the proofer/press is
the DESTINATION profile.
*** Application-Based Color Management: vector and
raster images are placed into Quark 5 or the latest versions of InDesign,
Illustrator, Freehand, or Photoshop. The application is able to color
manage its own "native" objects, as well as RGB TIFF images
(using either embedded, assigned, or assumed profiles). Questions: what
does one use for the assumed SOURCE profile? I assume the DESTINATION
profile is still the proofer or press. Can I use CMYK TIFF or does that
defeat the purpose of color management at the application level?
*** PDF-Based Color Management: one can set up Acrobat
Distiller to apply SOURCE and DESTINATION Profiles while converting
PostScript to PDF. I assume all embedded ICC profiles are honored, unless
specified otherwise.
*** Printer-Driver Color Management: there is an option
to use Color Management in the Print Dialog Box, on both Mac and Windows,
but my limited experience tells me to avoid it like VX gas ("the
plague" seems so outdated). Although, it might work OK when printing
Office application files or other non-PostScript data???
*** Queue-Based/Color Server Color Management: similar
to PDF-based, one prints PostScript to a print spooler, which then assigns
SOURCE and DESTINATION profiles.
*** In-RIP or Printer-Based Color Management: at this
point, the color has already been CMYK-separated, but the CMYK color space
for one device can be converted to simulate another CMYK device.
In-RIP color management is the workflow with which I am
most familiar and currently using. The results are good and it's relatively
easy to implement and maintain, although I believe additional benefits
would also be gained by using the Scanner-based or Photo-Editing
conversion. This appears to be the classic question: scan images into
"raw" RGB on a high-end drum scanner and then use ICC profiles to
convert to CMYK in Photoshop or let the scanner do what it was designed to
do... I have yet to hear a definitive answer to this one.
I'm also not sure we'll be switching from an
"Early-Binding" workflow (where color is converted into final
output space as soon as possible) to a "Late-Binding" workflow
anytime in the near future. As a print shop, 99.99999% of our work is to
one of several Heidelberg Speedmasters, all with similar color
characteristics.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Thomas Brainard
Baesman Printing Corporation
4477 Reynolds Drive
Hilliard, OH 43026
The United States of America
P: 614-771-2300
F: 614-771-2323
http://www.baesman.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
____________________________________________________________________________
Date: Wed, 26 Feb 2003 20:13:53 -0700
From: Andrew Rodney
Subject: Re: Color Management Workflows
on 2/26/03 3:09 PM, tbrain wrote:
I thought I had a good handle on SOURCE and DESTINATION
profiles, but
depending on the workflow choice below, I'm not
entirely sure I'd know
which profiles to use, particularly when it comes to
tagging images and
when to drop the embedded profile and reassign a new
one.
To make things more (or less) confusing, a profile can
be a source or a destination depending on where it1s used in the workflow.
For example, you have a scan and it1s tagged with a source profile (which
describes the meaning of the numbers provided by the scanner). Now you want
to convert into a Working Space (Adobe RGB). Simple. Now you1ve edited the
file and you want to print it out. Well you convert FROM Adobe RGB (the
source now but the destination previously) TO SWOP. So at one point Adobe
RGB was the Destination and at one point the Source.
What you need to keep in mind is you always need to
profiles (a source and destination). And this isn1t any different from the
old days prior to profiles. We had sources and destinations we just didn1t
use profiles.
*** Scanner-Based Color Management: images are
converted to CMYK during
the scanning phase, using the scanner's profile for
SOURCE and a
proofer/press for DESTINATION.
I wouldn1t recommend doing this (scanning into an
output space) but yes, that1s one possibility.
*** Photoshop Color Management: digital photos or
scanned images are
converted to CMYK within Photoshop (or equivalent). The
digital camera
or scanner is the SOURCE profile and the proofer/press
is the
DESTINATION profile.
Well yes but I don1t think it1s necessary to specify
the actual devices here. That is, you could have received RGB data from the
canner in your first example.
*** Application-Based Color Management: vector and
raster images are
placed into Quark 5 or the latest versions of InDesign,
Illustrator,
Freehand, or Photoshop. The application is able to
color manage its own
"native" objects, as well as RGB TIFF images
(using either embedded,
assigned, or assumed profiles).
Quark? Trying to do color management in Quark without
3rd party support is very dangerous. Quark is about as brain dead about
color as MacPaint 1.0 was <g>
Questions: what does one use for the
assumed SOURCE profile?
Untagged data is always a guess. It1s (as Bruce Fraser
likes to say) Mystery meat. You know the old saying about making
assumptions don1t you? Untagged files are just a means or playing a nasty
guessing game.
*** PDF-Based Color Management: one can set up Acrobat
Distiller to
apply SOURCE and DESTINATION Profiles while converting
PostScript to
PDF. I assume all embedded ICC profiles are honored,
unless specified
otherwise.
PDF? That1s where the wonder from Bolder will enter the
picture.
*** Printer-Driver Color Management: there is an option
to use Color
Management in the Print Dialog Box, on both Mac and
Windows, but my
limited experience tells me to avoid it like VX gas
("the plague" seems
so outdated). Although, it might work OK when printing
Office
application files or other non-PostScript data???
Not at all if properly written. Photoshop1s print
command is quite well behaved.
*** Queue-Based/Color Server Color Management: similar
to PDF-based, one
prints PostScript to a print spooler, which then
assigns SOURCE and
DESTINATION profiles.
Maybe. The big issue I have with this and the other
kinds of conversions you asked about after (In Rip etc) is you don1t get to
see what the conversions will do to the data. Doing in RIP (or Queue)
conversions is wonderful as a workflow enhancement for production but you
don1t get to see the color until the print comes off the printer. Can be
dangerous (or let1s put it this way, you don1t get much chance to edit the
file based on it1s output condition). While I recognize it1s wonderful for
moving a lot of files through a printer (and since the data is RGB,
repurpose is insured), you can1t really control the process to a fine
degree like opening a file in Photoshop, setting up a soft proof with the
output profile and editing (if necessary) based on the output device.
Andrew Rodney
____________________________________________________________________________
Date: Thu, 27 Feb 2003 11:30:52 -0700
From: Chris Murphy
Subject: Re: Color Management Workflows
On Wednesday, February 26, 2003, at 03:09 PM,
tbrain wrote:
*** Scanner-Based Color Management: images are
converted to CMYK during
the scanning phase, using the scanner's profile for
SOURCE and a
proofer/press for DESTINATION.
That destination profile immediately becomes the source
profile for the post-converted (now) CMYK image.
*** Photoshop Color Management: digital photos or
scanned images are
converted to CMYK within Photoshop (or equivalent). The
digital camera
or scanner is the SOURCE profile and the proofer/press
is the
DESTINATION profile.
Same as above.
*** Application-Based Color Management: vector and
raster images are
placed into Quark 5 or the latest versions of InDesign,
Illustrator,
Freehand, or Photoshop. The application is able to
color manage its own
"native" objects, as well as RGB TIFF images
(using either embedded,
assigned, or assumed profiles). Questions: what does
one use for the
assumed SOURCE profile? I assume the DESTINATION
profile is still the
proofer or press. Can I use CMYK TIFF or does that
defeat the purpose
of color management at the application level?
Use an assumed source profile that makes the document
look the way you want. Usually you want to make sure the document assumed
profile (if CMYK) matches the intended destination in order to prevent
conversion of native elements, like type. InDesign and QuarkXPress *will*
convert black only type into four color black if the document (source)
profile is not the same as the destination at print time.
*** PDF-Based Color Management: one can set up Acrobat
Distiller to
apply SOURCE and DESTINATION Profiles while converting
PostScript to
PDF. I assume all embedded ICC profiles are honored,
unless specified
otherwise.
Distiller is a little confusing. It doesn't really
have source and destination profiles per se - rather it depends on
context. If you are working with PDF spec 1.3 or higher, then profiles get
embedded, the document does not get converted so there isn't a destination.
EXCEPT in one instance where you specify converting the document to sRGB
(as the color management policy).
If you are working with PDF spec 1.2 things are
different and I'd avoid it.
*** Printer-Driver Color Management: there is an option
to use Color
Management in the Print Dialog Box, on both Mac and
Windows, but my
limited experience tells me to avoid it like VX gas
("the plague" seems
so outdated). Although, it might work OK when printing
Office
application files or other non-PostScript data???
Correct.
*** Queue-Based/Color Server Color Management: similar
to PDF-based, one
prints PostScript to a print spooler, which then
assigns SOURCE and
DESTINATION profiles.
Actually it's assuming a source, then converting to a
destination PRIOR to being handed off (by iQueue) to the printer.
*** In-RIP or Printer-Based Color Management: at this
point, the color
has already been CMYK-separated, but the CMYK color
space for one device
can be converted to simulate another CMYK device.
The color has not necessarily been separated to CMYK.
It is possible to send RGB PostScript to a RIP and for it to do separations
at RIP time. What you are saying (CMYK to CMYK conversion) is also
possible.
In-RIP color management is the workflow with which I am
most familiar
and currently using. The results are good and it's
relatively easy to
implement and maintain, although I believe additional
benefits would
also be gained by using the Scanner-based or
Photo-Editing conversion.
You're the first person I've ever heard of successfully
using in-RIP color management let alone PostScript color management. Do
tell!
I'm also not sure we'll be switching from an
"Early-Binding" workflow
(where color is converted into final output space as
soon as possible)
to a "Late-Binding" workflow anytime in the
near future.
In-RIP color management is synonymous with a
late-binding workflow, by definition, UNLESS it is only used for proofing.
So now I'm not following what you're saying.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Thu, 27 Feb 2003 11:36:45 -0700
From: Chris Murphy
Subject: Re: Color Management Workflows
*** PDF-Based Color Management: one can set up Acrobat
Distiller to
apply SOURCE and DESTINATION Profiles while converting
PostScript to
PDF. I assume all embedded ICC profiles are honored,
unless specified
otherwise.
I forgot to full respond to this. Embedded ICC profiles
in objects are stripped at print time and don't survive the conversion to
PostScript unless they were embedded in EPS files. However, even ICC
profiles in EPS files are ignored by Distiller. So embedded ICC profiles
are NOT honored by Distiller.
Embedded CSA's in EPS files however, are converted into
ICC profiles for those objects, by Distiller.
One thing to keep in mind is that a layout has multiple
objects and elements. Each of these objects can have a profile associated
with it, and PDF supports this. If the PDF has 20 images in it, plus text,
each text element can have a profile, and each of the 20 images can have a
profile. They could also share the same profile. The way profile embedding
works in PDF is that the profile is embedded once, and then referenced to
each object it applies to.
Once you have such a PDF, with ICC profiles in it,
those profiles are honored for display purposes in Acrobat no matter what
the Acrobat settings are (not sure about Acrobat Reader, haven't tried it).
At print time however, it is possible to ignore those embedded profiles,
pass them on as PostScript CSA's, or use them as sources for Acrobat to
convert to a specified destination profile.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Thu, 27 Feb 2003 17:26:56 -0500
From: "tbrain"
Subject: RE: Color Management Workflows
Chris Murphy wrote:
You're the first person I've ever heard of
successfully using in-RIP color management let alone
PostScript color
management. Do tell!
First, thanks for the feedback.
I'll try to clarify. What you call color management and
what I call color management may be two different things (surprise!).
Here's my primitive but, mostly effective,
"color" workflow:
-Scan images into CMYK on drum scanner.
-Place images into page layout.
-Create Postscript (or EPS in the case of
Rampage)
-RIP job in Rampage
-Ask Rampage to create proof data (TIF, CT, RTL)
using SOURCE and DESTINATION profiles.
Source = Kodak
Approval.
Destination = IRIS
(or color laser or DesignJet inkjet proof).
Asked in all earnestness: is this NOT a color-managed
workflow? It doesn't address all color management goals, but it does
address one primary goal: using ICC profiles (generated by Gretag-MacBeth's
ProfileMaker and Spectrolino/Spectroscan) to make various color devices
match a target device, in our case our Kodak Approval.
So, I guess this really isn't In-RIP color management.
It's a post-RIP process converting from one proofer's CMYK color space to
another. What would I call this instead? Is this a Device Link?
Thom
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Thomas Brainard
Baesman Printing Corporation
4477 Reynolds Drive
Hilliard, OH 43026
The United States of America
P: 614-771-2300
F: 614-771-2323
http://www.baesman.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
____________________________________________________________________________
Date: Thu, 27 Feb 2003 17:43:14 -0700
From: Andrew Rodney
Subject: Re: Color Management Workflows
on 2/27/03 3:26 PM, tbrain wrote:
-Scan images into CMYK on drum scanner.
Color Management is over now <g>. Well not
really. You can at least see the data in a color managed environment, get
an idea what your flavor of CMYK would look like on any other CMYK output
device you have a profile for. But you1ve gone from RGB to CMYK in one
operation (which does save time), the file is in an output space and I
expect you1re pretty much done (except for getting ink to hit paper of
course).
-Place images into page layout.
-Create Postscript (or EPS in the case of
Rampage)
-RIP job in Rampage
-Ask Rampage to create proof data (TIF, CT, RTL)
using SOURCE and
DESTINATION profiles.
Source = Kodak
Approval.
Destination = IRIS
(or color laser or DesignJet inkjet proof).
Ah, proofing! I forgot about that one <g>. Yes,
even in a closed loop CMYK centric operation, you still want to do that and
the CMS will help you. And yes, assuming you have good profiles for the
Approval and Iris, you can (as you probably already know), simulate the
Approval on the Iris when it1s not spilling ink all over the floor ;-)
Asked in all earnestness: is this NOT a color-managed
workflow?
I'll let Chris answer his opinion but I1d say yes, that
part of what your doing involves color management.
It doesn't address all color management goals, but it
does address one
primary goal: using ICC profiles (generated by
Gretag-MacBeth's
ProfileMaker and Spectrolino/Spectroscan) to make
various color devices
match a target device, in our case our Kodak Approval.
I agree. You1ll likely need to use some profile editor
to assist in 3forcing2 the Iris to match the Approval depending on how
close you want them to match. What you1re doing is called cross simulation
and I find that when I need to do this, some minor selective color edits in
the proofer (Iris) profile is usually necessary even with the best built
profiles (and I1d submit you have one of the best packages).
So, I guess this really isn't In-RIP color management.
It's a post-RIP
process converting from one proofer's CMYK color space
to another. What
would I call this instead? Is this a Device Link?
It could be done with a device link but that wouldn1t
change the basic concept of what you1re doing. A device link is just a
cousin of an ICC profile.
Chris, you1re up...
Andrew Rodney
____________________________________________________________________________
Date: Thu, 27 Feb 2003 21:24:53 -0500
From: Jim Rich
Subject: Re: Color Management Workflows
Thomas,
Let me ask this question, do the color results you get
in your workflow make your employer and clients relatively happy? And do
you use profiles to help you get those results in a dependable and straight
forward fashion?
In academic terms your workflow might not fit into
Chris's definition. Practically speaking, it sounds like you are having
success with using profiles to get good color results.
If that is the case and in terms of modern day color
management tools, it sounds like your workflow is color managed. Though,
the way you work might not fit into an exact definition of color
management. And from your first post, it sounds like you are using the
profiles to your advantage for scanning, page layout and proofing (though I
would stay in RGB and do the image editing before converting to CMYK).
Jim Rich
______________________________________________________
Date: Thu, 27 Feb 2003 17:56:20 -0700
From: Chris Murphy
Subject: Re: Color Management Workflows
On Thursday, February 27, 2003, at 03:26 PM,
tbrain wrote:
Asked in all earnestness: is this NOT a color-managed
workflow?
It is color managed. And not because ICC profiles are
being used for proofing, but because there is a clearly defined workflow
for handling color.
It doesn't address all color management goals, but it
does address one
primary goal: using ICC profiles (generated by
Gretag-MacBeth's
ProfileMaker and Spectrolino/Spectroscan) to make
various color devices
match a target device, in our case our Kodak Approval.
Specifically
So, I guess this really isn't In-RIP color management.
It's a post-RIP
process converting from one proofer's CMYK color space
to another. What
would I call this instead? Is this a Device Link?
Hmm terminology - what fun :) Umm, I think I'd classify
it as a prepress color management based workflow product since you're
referring to Rampage. In-RIP color management refers to color management
actually occurring in the RIP itself at RIP time. This is generally quite
rare, and mostly useful only in proofing scenarios because of the near
total lack of control. Color management workflow products for prepress have
quite a bit more control than the in-RIP category.
DeviceLink profiles are a totally separate class of ICC
profile where the source and destination are concatenated into a single
DeviceLink profile that is unidirectional and doesn't contain a PCS
(conversions occur directly from source to destination space without using
CIELAB or CIEXYZ as the connection space between the two device spaces). I
think Rampage supports DeviceLinks in addition to the Display, Input and
Output class of profiles (device profiles), but I'm not sure. There can be
significant advantages to using a DeviceLink in proofing and repurposing
scenarios, instead of two Output device profiles (as source and
destination). We discuss this on 427.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Thu, 27 Feb 2003 19:33:49 -0700
From: Chris Murphy
Subject: Re: Color Management Workflows
On Thursday, February 27, 2003, at 03:26 PM,
tbrain wrote:
It doesn't address all color management goals, but it
does address one
primary goal: using ICC profiles (generated by
Gretag-MacBeth's
ProfileMaker and Spectrolino/Spectroscan) to make
various color devices
match a target device, in our case our Kodak Approval.
I wrote:
Specifically
Yeah - it probably would be a good idea for me to
finish my sentences...
Specifically using ICC-based color management here
*GENERALLY* makes it pretty clear cut and dried that this part of the
workflow is color managed. Other areas of the workflow where ICC-based
color management is not being used does not inherently mean that the
workflow is "not color-managed." When ICC-based color management
isn't being used, color management may still be happening, you just have to
look a little deeper at how color issues are being handled by human blobs
and their equipment.
Likewise, even if you use ICC-based color management,
it is possible for the workflow to NOT be color managed. One can use
ICC-based color management improperly and have color mismanagement. Color
management isn't self-audited.
The summary here, and bottom line is that "color
managed workflow" as a term is something that is defined in context. I
have a tendency to look at things as a combination of equipment, tools and
humans. Color management is typically seen as just equipment and tools, but
I prefer to include a human element into the definition because humans are
the ones doing the managing. If they aren't doing the managing, this stuff
simply doesn't work push button (and even if it did, who's pushing the
buttons?).
I digress...
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Fri, 28 Feb 2003 08:23:59 -0500
From: "tbrain"
Subject: RE: Color Management Workflows
Jim,
Yes. In general, my employer and clients are very happy
with the proofs.
Since we've switched to Rampage's ICC profile workflow
(post-RIP, pre-Proof...PRPPICCCM Workflow), it provides a more consistent
process for managing color anytime we add a new color proofer/device to the
mix. (As opposed to the old method where we had to learn the intricacies of
each devices color tools.)
As Andrew pointed out yesterday, using raw unedited ICC
profiles will get you close, but for an ideal "match," some
editing of the ICC profiles has to take place. And we do edit our profiles
in Gretag-MacBeth's Profile Editor. It usually takes a few stabs at the
color until we're satisfied. (As I told Andrew, it's hard to say when a
color "match" is as good as it can be...usually I find it's time
to quit when I discover that our fourth attempt is better than our sixth.)
Unfortunately, there are times where the proof doesn't
quite match the press sheet close enough. It's not often, but when it
happens it does leave us scratching our heads. Oh sure, we can pull out our
GATF press sheets and show the customer how great our gray balance is and
how well the GATF images match from proof to press, but there are still
situations where we feel the color match could be closer.
I guess, deep down, we all know there is no such thing
as a perfect color match... But, it would be nice to know that we've done
the best match possible. Some of that's luck. Some of it's skill.
Experience is also critical. I suspect many of us are self-taught, so we
never quite know what it is that we don't know.
Thom
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Thomas Brainard
Baesman Printing Corporation
4477 Reynolds Drive
Hilliard, OH 43026
The United States of America
P: 614-771-2300
F: 614-771-2323
http://www.baesman.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
____________________________________________________________________________
Date: Fri, 28 Feb 2003 09:34:42 -0500
From: "tbrain"
Subject: RE: Color Management Workflows
So... If one wanted to learn more about implementing
color management into "real world" situations--say at a client's
location--where would one go for hands-on training?
I've taken note of GATF/PIA's Color Management
Workshops, but the descriptions make it sound like we're just going to
learn how to use a variety of spectrophotometers and profile packages to
make ICC profiles.
Not that my ICC profile creation skills are
"expert" level, but I'm more interested in workflow
implementation, not profile creation.
Of course, there's the annual Color Management
Conference, which I think takes place in Phoenix in December. That's pretty
far off, and I'm afraid it would simply cover esoteric topics such as
"metamerism" and "CIE LAB vs. XYZ LAB," topics that are
of more importance to color management product developers and vendors than
end users.
How does an end user, say one of my clients,
learn to implement color management? So far, I've seen two books on color
management: REAL WORLD and GATF's. Both are good, but books only take one
so far...
Thanks,
Thom
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Thomas Brainard
Baesman Printing Corporation
4477 Reynolds Drive
Hilliard, OH 43026
The United States of America
P: 614-771-2300
F: 614-771-2323
http://www.baesman.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
____________________________________________________________________________
Date: Fri, 28 Feb 2003 10:53:50 -0500
From: Jim Rich
Subject: Re: Color Management Workflows
Thom,
As you have pointed out there are different levels of
training needs.
The GATF/PIA's Color Management Workshops are very good
and cost effective for introducing someone to color management and
getting them thinking the right way to make it work. GATF even offers an
advanced class that is quite good.
I find, once you get to the next level you have to
either start networking with more advanced color management types or hire
an expert to come to your site and train you on your workflow. If you
have never hired a consultant then you might want to check out some tips I
have for hiring one. http://www.photoshopfocus.com/tips.htm
Jim Rich
____________________________________________________________________________
Date: Fri, 28 Feb 2003 11:58:05 -0500
From: Kim Oravecz
Subject: RE: Color Management Workflows
Another place you might want to check out is the
Graphics Intelligence Agency:
http://www.graphintel.com/
They offer 2 day color management seminars and then
they also offer one specifically for Gretags Profilemaker both at their
site -or- they will come out to you.
. . . Kim
Adobe Photoshop training classes are taught in the US by Sterling Ledet & Associates, Inc.