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91
Beginner Talk / Re: Self Printing Worflow & Color profiles
« Last post by GarryP on December 28, 2017, 04:37:08 pm »
I would imagine that the article could be long and complicated but it doesn't need to be very detailed at the beginning.

It could start with a disclaimer such as: "This process has been verified with the equipment stated at the bottom of the article but might not work in every situation. Always check with your print shop first."
Then it could have a short glossary, like you have given, with links to further reading.
After those it could be a list of: Do this; then check this; then do that; then switch this on; etc. A bit like a check-list.

Once the article is finished, people could add to it giving some extra information and notes about different circumstances and kit.
I don't think many people want to learn about this sort of stuff. Mostly they just want to know what to do so they can get on with the document itself and not worry about the technical details.
I realise that the details are very important but if someone can just do what a check-list says - maybe with a few changes - they are more likely to try it rather than just thinking that it's all too complicated and give up.
As long as the disclaimer is written clearly enough then people can at least decide if they want to try it.

The important thing is that it would need an expert such as yourself to start the whole thing rolling. Anyone could probably cobble something together but it needs the experience of someone who really knows what they're doing to make sure people are pointed in the right direction from the start.
92
Beginner Talk / Re: Self Printing Worflow & Color profiles
« Last post by Nermander on December 28, 2017, 04:14:25 pm »
I have been thinking of writing a "CM for dummies" article for the wiki, but have never had time.

But the key points are:

1.
Pixels in a digital image neve have a color, they have a value/number.

Which color that value is supposed to represent is defined by the used colorspace. The colorspace is a translation from a binary value (RGB or CMYK) into a more complex color representation (like CIELab).

So as long as you are only working with the image, it is just a matter of colorspace.

This is valid for both pixels in bitmap images as well as colors defined in Scribus.

But as soon as you are going to display the color in some way, things become more complicated.

2.
A color profile hand tells "how is this (e.g. CIELab) color represented on this device?".

For a scanner a color profile tells "To what RGB value will this (e.g. CIELab) color translate?".

For a printer a color profile means "What CMYK values are needed to represent this (e.g. CIELab) CIELab color with this printer on this paper?".

3.
Now, the catch here is that every single color in the (e.g. CEILab) colorspace cannot be represented on every printer and paper combination. The CIELab can be considered to be absed on what the eye can see, not what the inks can created. And RGB or CMYK colorspaces are even narrower.

See the images on this page
https://en.wikipedia.org/wiki/Color_space

And that is where the "rendering intent" comes to play. It tells the software "what to do with colors that cannot be translated".

https://en.wikipedia.org/wiki/Color_management#Color_transformation


And the reason for not using colorspaces like CIELab in the digital images is of course space. Images would become a lot bigger if we used CIELab or something like that for each pixel.
93
Beginner Talk / Re: Self Printing Worflow & Color profiles
« Last post by GarryP on December 28, 2017, 02:17:48 pm »
If this workflow - or something like it - could be generalised and verified then I think it would make a great article for the wiki.

If there was a single article showing what to do in order to get something professionally printed from Scribus then I'm sure it would help a lot of people. Obviously it would need a lot of boxouts explaining differences between certain things but it would be a very useful starting point.

A lot of people - me included - have no idea what all of this colour management, ICC profiles, ICM stuff is really about. Most people don't get stuff professionally printed on a regular basis so why would they know about it? If there was some kind of check-list that people could use to make sure they have done everything they can to ensure something could be properly printed then it might make people a lot more comfortable with using Scribus for that sort of work.
94
Beginner Talk / Re: Self Printing Worflow & Color profiles
« Last post by manufv on December 27, 2017, 07:34:32 pm »

hi folks,

Finally, I've got it.  Here is my finale workflow.
Here is my workflow :
1) prepare images into Lightroom (LR) which is working mode RGB, profile ProPhoto, 16bit
2) export images from LR as working.tif/RGB/ProPhoto embedded ~full size/resolution/no sharpening
3) compose the book in scribus ~color mngt enabled ; my screen is calibrated
4) when done, via scribus.scripter,
4.1) resize/crop working.tif images regarding frames composition and generate/saveas a final.tif image ;
4.2) replace working.tif by final.tif into frames (close scribus)
5) sharpen final.tif image with third tool (Nik Output Sharpener)
6) reload scribus ~ load final.tif image, still RGB/ProPhoto

7) Export pdf for self-printing on my Epson Surecolor P800 (rgb printer, rgb icc profile for my paper)
7.1) General : PDF/X-3 ; (PDF/X-3: individual objects can be present in ICCbased color spaces, including RGB and CMYK objects with embedded ICC profiles.)
7.2) Colour :
-- Output intended : Printer (greyd'out - no modification pdf/x implicit for printer)
-- Convert Spot colour : Uncheck
-- Use Custom rendering : uncheck
-- Solid colour : Use color profile ProPhoto/Perceptual
-- Images :
--- Use colour profile : checked (forced) ;
--- Do not use embedded colour profiles : unchecked (means : Use embedded colour profile)
(After internal check, /ColorSpace /DeviceRGB and pdf's images are ProPhoto profile embedded)

8) Open with Adobe Acrobat Reader

9) Print with options :
Acrobat :
-- General : Real size
-- Advanced : let Printer determine color : Checked  ; (Acrobat pass the profile id / rendering to the driver)
Epson Printer Driver :
-- General : Mode ICM ;
-- Advanced ICM : ICM host (epson driver receive profiles from app (see 'let printer determine color')
-- Advanced : Display all icc profile : Checked
-- Select rendering (perceptual),...
-- Select desired printer/paper icc profile     ;D
================

With that workflow, There is no mode/color treatment between LR until printer driver.
Perfect !

Thanks for your precious advice.
manu
95
General Discussion / Re: Clickable TOC / document outline in PDF
« Last post by GarryP on December 27, 2017, 11:59:57 am »
As far as I know, what you want is not possible with Scribus (with, or without, scripts).

You can use PDF bookmarks that will show in a navigation pane in a PDF reader - if the PDF reader has that functionality - but there is no functionality within Scribus for producing any kind of hierarchical structure. The list of bookmarks is a simple flat list that is ordered by Scribus with no way for the user to change that order or specify a structure.

This Scribus-ordering - rather than user-ordering - can be seen in the way that you can't define where something will come in a TOC. The TOC entries are listed in the order that Scribus "sees" the frames rather than their position on the page or some other means. (See https://bugs.scribus.net/view.php?id=7426 ) Also, Scribus has no hierarchical TOC capability; a Scribus TOC is always a flat list.

If the TOC capabilities of Scribus were enhanced to allow for a hierarchy then I don't think it would be a huge amount of extra work to also - optionally - automatically create a PDF bookmark for each text frame with a TOC attribute. This could be done on-the-fly at the stage when the PDF was produced so as to not have stray bookmarks left around when the user modifies attributes. (I haven't thought about this much until now and I have no idea how a hierarchical structure could be user-specified.)

Enhancements to the TOC functionality of Scribus would benefit a lot of people. The current sparseness of functionality is something that may be putting people off from using the software. (People have asked questions about this sort of thing in the past and mentioned that if the functionality isn't there then they will have to use something else.) Of course, not all documents need a TOC - never mind a hierarchical TOC - but the inability of Scribus to produce anything other than a simple flat list that can't be user-ordered is a shortcoming of the software that needs to be addressed if it is to be considered for professional use.

You could try having a look through Mantis http://bugs.scribus.net/ to see if there are already any relevant open issues. Somebody might already have suggested pretty much the same thing. If not, you could add a request yourself and help to guide Scribus towards new functionality.
96
General Discussion / Clickable TOC / document outline in PDF
« Last post by eudoxos on December 27, 2017, 08:24:36 am »
Many PDF files, e.g. those produced with LaTeX, have handy navigation through the document via hierarchical TOC in the PDF viewer side pane (not in page area itself). As far as I understand, this feature is distinct from PDF bookmarks. Is it possible to produce & export this kind of navigation information with scribus (trunk)? I don't mind doing it (mostly) by hand or with scripting. Thanks for pointers!
97
Bitmap Images / Re: Rounding error on bitmap edges?
« Last post by anna105 on December 27, 2017, 02:35:24 am »
Finally I solved my own problem!

First I stripped the ICC profile from my input image with imagemagick:
  convert input.png -strip input_new.png

Then I imported this in Scribus and saved my export file:
  File --> Export --> Save as Image --> No Background must be checked.

I made two export versions. PNG and BMP. The generated PNG has now an alpha channel. The BMP is fine!

I think it is definitely a bug. My original PNG is not transparent but Scribus makes it on two edges (semi)transparent and one can see the background. If you need a background it makes sense that you get transparent output files. But if I don't need the background, I don't need transparency too. Moreover the alpha channel is incorrect on some edges.

See my attachments. Can you reproduce it? I am using Scribus 1.5.2 on Linux.
98
Beginner Talk / Re: Self Printing Worflow & Color profiles
« Last post by utnik on December 26, 2017, 05:59:58 pm »
hi manufv

can you be more specific about color mngt/export settings ?

then any idea, how to spool it with a capability to specify my icc printer/paper profile?

first you need to put the profile for the chosen printer/paper combination into the folder listed under 'preferences' → 'general' → 'paths' → 'icc profiles' then scribus should find it.

then you export your .pdf file:
  • in the 'general' tab you select one of the .pdf variants except .pdf/x-1a (as this is strictly cmyk related)
  • under 'colors' select 'printer' and check both boxes labeled 'use color profile' if the images aren't converted to the correct profile before, you need to check 'do not use embedded color profiles' as well.
  • for images the standard rendering intent should be 'perceptual', for solid colors 'relative colorimetric' is good for most cases. (if you have sensible colors in a logo or other ci related items, absolute colorimetric will berequired, and for artwork with seamless transitions between images and solid colors you need the same conversion for the two of them – wich one may vary…)
  • don't forget to select your profile for both groups of colors
  • if your layout contains spot colors, convert them to process colors
What I have learned in the past is that "for printer" makes a CMYK PDF, and there have been dozens of discussions that the name of the setting is misleading.

what i have learned out of those discussions (from one of the scribus devs) is: 'for printer' really means for printer, as long as it is within a color managed workflow…

utnik
99
Beginner Talk / Re: Self Printing Worflow & Color profiles
« Last post by Nermander on December 26, 2017, 05:11:37 pm »
NO!!! – just try it!
the resulting .pdf file is an rgb file with the colors converted to the color space of the selected rgb profile – and you will see the difference even if you don't have a professional tool to verify colors…

I don't have Scribus installed on this machine, so I cannot try.

What I have learned in the past is that "for printer" makes a CMYK PDF, and there have been dozens of discussions that the name of the setting is misleading.
100
Beginner Talk / Re: Self Printing Worflow & Color profiles
« Last post by manufv on December 26, 2017, 05:01:03 pm »
thanks nermander, utnik,

I'm ok with your argument, to export a pdf.x3, mode RGB.
can you be more specific about color mngt/export settings ?

then any idea, how to spool it with a capability to specify my icc printer/paper profile?
 
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