Hal V. Engel
Thu Feb 15 19:42:44 CET 2007
On Thursday 15 February 2007 06:25, Aurelien Roux wrote:
> OK, thanks for all of that.
> I use scribus-ng packaged for Ubuntu 64 on Debian-AMD64.
On Linux your monitor calibration and profiling options are very limited.
One approach used by some users is to dual boot the machine and use Windows
software and a color meter to create your profile(s). Then use these in
Linux. There are a number of options and price points for the hardware and
software to do this starting at about $50 street price for the Pantone
(really X-Rite) Huey. This will only work on x86* hardware and you need to
purchase Windows which is a significant additional expense (IE. this makes
the Huey closer to a $200 option for a Linux user).
I have also tried to use VMWare to run a Pantone EyeOne Display LT in a
Windows session on my Linux desktop. Never got this to work as the software
would always hang just before it wrote out the profile. But in theory this
should work better then dual booting to Windows if you can find software that
will run. This approach might work on non-x86* hardware if you can get the
VM to correctly emulate an x86 environment and if the profiling software will
run to completion but you will also need to purchase Windows for this option.
The last current option is to use ArgyllCMS and one of it's supported devices.
The number of devices is limited and of the affordable ones none are in
current production. For example ArgyllCMS supports the X-Rite DTP-94 which
sells for $199 for the meter only but which is now discontinued. You might
be able to still get one of these meters but I expect that none will be
available in a few months.
X-Rite also sells the EyeOne meters which do have a Linux support library.
But this library has never been released and at this point obtaining a copy
of the library is all but impossible. In addition the license restrictions
on the library are currently such that it can not be used with open source
software or even closed source software that is distributed as source code
and does not contain redistribution restrictions that would make it
impossible for Linux distros to include the software.
In short there would likely be more options available for Linux users if there
were hardware vendors who would either release the low level interface specs
for there hardware or create and release high level interface libraries for
Linux/Unix systems. X-Rite has released the low level interface specs for
some of their devices but appears to be discontinuing most of those for
which they have done this in the past.
> Le Thu, Feb 15, 2007 at 01:09:08AM -0800, Hal V. Engel a ?crit :
> > On Thursday 15 February 2007 00:09, you wrote:
> > > Hi !
> > >
> > > I've read some tutorials about ICC-Profiles, and I use them (especially
> > > LStar) since a little time, but anyway it keeps quite blury for me, and
> > > as I've a dilemma with a printer service (who is very bad, indeed), I'd
> > > like to understand it a little more to be sure of what I'm doing before
> > > sending the pdf to the printer agency.
> > >
> > > So here are some questions :
> > >
> > > 1. What are the advantages, specifities, etc. of each profile (in fact
> > > I use sRGB, ECI, and LStar profiles) ?
> > The profiles used in your work flow have to be specific to the devices
> > used in your work flow. Profiles like sRGB and ECI are generic profiles
> > that are almost never correct for the devices in anyones work flow. So
> > for example you need to have your monitor correctly calibrated and
> > profiled to have a good monitor profile. This can only be done using a
> > hardware measurement device and software that supports that device to
> > calibrate and profile your monitor.
> > In the case of the printer service they must either give you a profile
> > for their printer so that you can supply them a device specific document
> > (IE. you convert it to the color space they need before you give them the
> > file) or they must color manage the print work flow and convert your
> > documents from whatever color space these are in to the correct color
> > space for their printer. The better print services will give you
> > explicit instructions about what they want you to do to get the
> > images/documents properly color managed for their work flow.
> > > 2. How can I be sure of what I'm supposed to get on the paper ? (I've
> > > to add that my graphisms are done with Gimp, so in RGB, and then it's
> > > scribus which turns them to CMYK) I thought that, as I used an
> > > ICC-profile and my screen was well-configured, I was supposed to get
> > > the same as I saw on the screen, but in fact, as I gave the files to a
> > > printer agency to print some tests, I didin't get the same, and more, I
> > > didn't get the same for the same profile one day to the other. I tried
> > > to explain the printer agency that it was their fault, but they don't
> > > want to hear it, so I want to be sure.
> > If you have not used a hardware measurement device to calibrate and
> > profile your monitor you can not be sure your monitor is correct or that
> > the various pieces of software you are using are doing the right thing.
> > In addition it is actually much more complex since you must also have the
> > lighting in the room where you work on the monitor correctly setup and
> > you must also have a correctly setup light source for viewing the printed
> > output for this to all really work.
> > If you are seeing different results for different runs of the same
> > document with the same color management settings (IE. profile) then you
> > need to find another print service. Also if the print service can't tell
> > you which profile they want the document converted to before they get it
> > then they likely do not understand color management and you should not be
> > using them.
> > > 3. How can I be sure my screen is well-configured ?
> > See above for the general answer. You don't say what platform you are
> > running and getting a detailed answer depends on that information.
> > > Thanks.
> > Learning color management even at the level needed by a user is a
> > significant task with a large learning curve. Most print services only
> > deal with a very small number of customers, if any at all, who have even
> > a basic understanding of color management and in many cases the print
> > service has no working knowledge of color management. I worked with a
> > customer who was using a photo that was prepared on my equipment. The
> > photo was properly color managed and the monitor was well calibrated and
> > profiled. But the printed results were way too dark. The print service
> > asked that the image be supplied as a CMYK image rather than an RGB image
> > and when I asked him what color space he wanted it converted to (meaning
> > a specific CMYK color space) and he didn't have any idea what I was
> > talking about. So I asked him if he could supply a profile for the
> > printer that these would be printed on and again he had no idea what I
> > was asking him for. He simply did not have any idea what color
> > management was and how to communicate with a customer who did understand
> > it (The customer picked the print service and this could not be changed).
> > On the other hand I have used print services that not only understand
> > this stuff but when asked about it they already have a document and/or a
> > web page that has explicit details about what the customer needs to do to
> > have their images/documents ready to fit their CM work flow. The results
> > from these services have been of very high quality with no surprises.
> > Which I suspect is exactly what they want to have happen and exactly what
> > you as a customer should expect when you get to the point where you
> > really do understand color management.
> > Hal
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