[Mageia-discuss] Gimp printing

[Liam R E Quin]

On Sat, 2011-08-20 at 08:30 -0400, Gary Montalbine wrote:

> P.S. I noticed that the printed pictures in ML are slightly lighter that 
> shown in Gimp. Is there some type of program that calibrates printer 
> with monitor?

Yes. To calibrate a monitor properly, you need hardware such as a
Spyder, which can produce an ICC colour profile for the device. You can
find them on eBay. Some of these devices are said to work in Linux,
others are Mac and Windows only. Years ago they were pretty much all Mac
only, since that's what the graphics design profession all used.

The cheaper LCD monitors have only 6-bit-per=channel colour in them, so
there are many colours that the computer can represent that the monitor
can't display. Unfortunately, there are also many colours they _can_
display that can't be printed (and vice versa).  The range of colours a
device can print or display is called its gamut. Monitors and printers
generally have overlapping gamuts, but not identical, and the cheaper
monitors tend to have much less of an overlap.

To get anything like reasonable sRGB coverage (close to the 8-bit
default colour profile used by GIMP) you typically need to spend USD$600
or more... look for an "IPS" display for example. But you'll still need
to do calibration if you're doing serius print work.

If you don't want to spend the money, or don't have it, or would rather
buy shoes and socks :-), then search the Web (or check the CD that came
with the monitor and printer) for .ICC or .ICM files; in Gnome 2 you can
use [gnome]->system->preferences->color profiles to load them, and you
can also tell gimp (and I think cups) about them.

If you have a scanner you can do the same with that, and then print
something and scan it and compare the files -- it's OK if they are a
little different, especially if you grabbed someone else's ICM files
rather than the ones for your individual device, because devices vary in
manufacturing and with age, and because the colour gamuts differ.

In gimp, image->image properties can show if there's an embedded colour
profile in the image. If so, you can use exiftool on the command-line to
remove it and see if that helps with printing; see also
gimp'sview->display filters->colour management configuration, and
edit->preferences->colour management.

Liam


-- 
Liam Quin - XML Activity Lead, W3C, http://www.w3.org/People/Quin/
Pictures from old books: http://fromoldbooks.org/