[Scribus] Colour management questions

[Plinnell]

On Wednesday 01 December 2004 12:59, David Purton wrote:
> Hi,
>
> I'm trying to get colour management working, but I'm sure I'm doing
> something obvious wrong, since colours do not look like I expect them
> to.
>
> I'll use cyan as an example, but no colours look like what I expect.
>
> I would like the solid colour cyan to look like process cyan, but
> instead it seems to look more like the nearest colour you could get in
> cmyk to RGB #00FFFF. My best guess is that Scribus does not seem to
> differentiate between RGB and CMYK colours and everything is treated as
> RGB and then corrected to the nearest cmyk colour. Is this right, or am
> I up the creek? Regardless, how can I get scribus to display cyan so
> that it actually looks like process cyan? (Roughly the sort of colour
> you get if you export a solid cyan square from scribus to a cmyk pdf.)
>
> The second question is perhaps related. If I create say a filled cmyk
> tiff which is just cyan, and also an rgb tif of just rgb #00FFFF and
> import both pictures into Scribus, they look the same and again neither
> looks like the process cyan colour mentioned above that I want.
>
> Unless I'm really confused, I would have expected the two bitmaps to
> look different - the rgb with the nearst approximation to #00FFFF and
> the cmyk looking like process cyan.
>
> lcms is working properly, beacuse I get exactly the behaviour I want
> using the separate plugin in the gimp. If I separate the rgb file and
> then use the separate plugin to view a proof I get an image that looks
> reasonably similar to what scribus shows on screen for both the rgb and
> cmyk tif. If I create a separated image of 100% cyan in gimp by manually
> making up the 4 layers like what the separate plugin does and then get a
> proof, I get my process cyan like colour.
>
> So what am I missing in Scribus?
>
>
> If it helps, I use CorelDRAW at work for prepress work in publishing
> process colour textbooks, so all the colours we use a pantone process
> colour SWOP guide to choose colours, which look much the same on screen.
> (Precise colour control is not necessary for our work, I'm used to
> things looking more or less right automagically.)
>
>
> cheers
>
> dc
>
>
> This is my setup:
> liblcms 1.13 & Scribus 1.2cvs on debian/unstable
> Activate Colour Management is selected
> System Profiles:
>         Pictures:      Adobe RGB (1998)
>         Solid Colours: Adobe RGB (1998)
>         Monitor:       Sony Trinitron Std D93
>         Printer:       Euroscale Coated v2
> Rendering Intents:
>         Monitor:       Relative Colorimetric
>         Printer:       Percetual
> Simulate Printer on the Screen is checked
> Mark Colours our of Gamut is not checked
> Use Blackpoint Compensation is checked

Hi,

As a first start try these settings and see my comments:

System Profiles:
Pictures:      sRGB (unless they are tagged with Adobe RGB in Photoshop) 
Solid Colours:  sRGB
Monitor:     Sony Trinitron Std D93       <<--- how was this profile created ?
Printer:       Euroscale Coated v2
Simulate Printer on the Screen is checked
Mark Colours our of Gamut is not checked
Use Blackpoint Compensation is checked    (experiment with this off)
Rendering Intents:
Monitor:       Relative Colorimetric
Printer:       Percetual     <<--- try Relative Colorimetric


Reason,  Scribus does not use Adobe RGB for color internally.

I hope that helps,

Peter