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Scribus => Beginner Talk => Topic started by: Jan Walraet on January 15, 2024, 08:46:15 PM

Title: Scribus 1.6.1 toggle the colour management system
Post by: Jan Walraet on January 15, 2024, 08:46:15 PM
When I press the Button in the toolbar of Scribus 1.6.1 that toggles the colour management system nothing happens.

What can be the reason?


Title: Re: Scribus 1.6.1 toggle the colour management system
Post by: AdmFubar on January 16, 2024, 04:03:37 AM
Check you have activated color management in the preferences. Look in File/Preferences/Color Management drop down menu.
Title: Re: Scribus 1.6.1 toggle the colour management system
Post by: Jan Walraet on January 16, 2024, 09:31:33 AM
I have activated Colour Management in both:

- Preferences
- Document Setup
Title: Re: Scribus 1.6.1 toggle the colour management system
Post by: utnik on January 16, 2024, 12:43:28 PM
hi jan

you need to check 'preferences' → 'color management' → 'simulate printer on the screen' or for existing files 'file' → 'document setup' → 'color management' → 'simulate printer on the screen'.

utnik
Title: Re: Scribus 1.6.1 toggle the colour management system
Post by: Jan Walraet on January 16, 2024, 10:51:10 PM
I have done that and I see no difference: nothing happens.

What should I have to see if I press that button?
Title: Re: Scribus 1.6.1 toggle the colour management system
Post by: AdmFubar on January 16, 2024, 11:21:24 PM
then most likely there isnt anything in your document that has any color that is outside of the color space of your printer.
In the prefs, are there any color  profiles selected for the printer or display?
Title: Re: Scribus 1.6.1 toggle the colour management system
Post by: a.l.e on January 17, 2024, 07:45:34 AM
 well, i would ask the opposed question: what do you expect to see? (and miss...)

color management is not a button that will magical improve your pdfs...

https://en.wikipedia.org/wiki/Color_management
Title: Re: Scribus 1.6.1 toggle the colour management system
Post by: Jan Walraet on January 18, 2024, 11:40:56 AM
then most likely there isnt anything in your document that has any color that is outside of the color space of your printer.
In the prefs, are there any color  profiles selected for the printer or display?

 
 I don't think so. Where can I find this?
 

well, i would ask the opposed question: what do you expect to see? (and miss...)
color management is not a button that will magical improve your pdfs...
https://en.wikipedia.org/wiki/Color_management

 
I don't know because nothing happens.

I noticed in the right side at the bottom a place with the mention in it "100%" filled with blue blocks. When I push the Colour Management Toggle a spinning ring appears for 5 seconds and then the the blue filled space empties en stay empty. But further nothing happens.

When I put an Image frame in my document with an image I have under Colour Management (F3) the mention "Input Profile" with the mention that it is "Embedded sRGB" and under "Rendering Intent" the mention "perceptual".

I tried to print some old documents. There is no problem but I suppose the colors are defined inside the documents or the images. When I push Colours and Fill there is only Black, White and Registration. I can add colors (both CMYK and RGB) but is this meaningfull?

Colour Management is apparently very complicated. Where can I find a clear explanation for interested people like me without to much technical stuff?
Title: Re: Scribus 1.6.1 toggle the colour management system
Post by: Nermander on January 18, 2024, 12:42:03 PM
Color management is "simple" but also very difficult.

The whole point is that a computer does not handle colors. What we consider colors are just numbers, we can call them color values.

The point of color management is to try to make a color value to look the same on different "output devices" like screens and printers. What further complicates things is that screens use RGB and printers usually CMYK. That means there are RGB color values that are impossible to represent in CMYK and also CMYK color values that are impossible to represent in RGB. This is called "out of gamut".

The way color management solves this is called color profiles. A color profile is essentially a translation table saying:

"To properly show the color of this color value on this device it shall be adjusted to this other color value."

So it is all a matter of conversions back and forth using the color profiles. Without proper color profiles you are better off just sticking to RGB, because most printers have their own built in color profile for handling RGB.

The button you are talking about I think is trying to "simulate how it will look on a printer with the selected color profile", and unless you use weird color values there will probably be no change because the printer will correctly handle the color values you are using.