[Scribus] Colour management questions

[Plinnell]

On Thursday 02 December 2004 13:36, David Purton wrote:
> Here is a links to an image, that will better explain what I meant in my
> original email:
>
> http://marshwiggle.net/scribus.png
>
>
> cheers
>
> dc

Hi,

That looks *exactly* like I would expect.

One very important point, GIMP while it can generate CMYK separated TIFF's, 
cannot yet display accurately for the gamut compression in the conversion 
from > RGB > CMYK Euroscale. The current Color Management while it uses 
littlecms, does not yet have all the pieces. So opening a CMYK TIFF in GIMP 
is not really showing what really is going to print to CMYK.

What the current GIMP setup does is do a conversion to sRGB and dump that to 
screen without an correction for the monitor. *That*  is the missing piece at 
the moment.

Two other issues affecting your perception of what is "correct":

Your monitor profile is not accurate for your system. (Very likely -  without 
a good accurate monitor profile, all bets are off.)

Littlecms is overcompensating for the gamut compression (Possible, but the 
delta E (error of the conversion) has been measured to be very accurate in 
lcms))

In my experience, lcms + scribus with carefully made monitor profiles created 
by Monaco and Gretag tools under Windows, *very* accurately predict the gamut 
compression when printing to a real CMYK printer. 

A good example was the previous Scribus logo, when printed to a carefully 
profiled printer (EFI RIP printing to 1200 DPI CMYK laser), the screen to 
print match was within 5% of what I saw in Photoshop 6 with the same 
hardware/printer combo, using the same PDF output.

Luckily, I have a client who has let me play with these nice toys for real 
world testing.

Cheers,
Peter