[Scribus] PDF export turns pictures pale

[David Purton]

On Wed, Feb 02, 2005 at 08:24:48AM +0100, Eilert wrote:
> The other day I exported some pages to PDF. There were 3 photos on the 
> pages, and as I wanted them to come out as good as possible, I turned 
> the choice to "maximum" quality.
> 
> Much to my surprise, the photos became rather pale then, i. e. contrast 
> was week, no dark colours (gamma setting?). Choosing a poorer quality 
> let the pictures appear right again.
> 

By poorer quality, perhaps you mean selecting "screen/web" as opposed to
"printer" when creating the PDF?

Is this the case?

Thinking the difference between screen/web and printer is in quality
seems to be a common mistake people make. Perhaps Scribus should look at
renaming these options?

The difference between screen/web and printer, is not in quality, but in
colour model. screen/web will produce an RGB colour based PDF, while
printer will produce a CMYK colour based PDF.

> Did I detect a bug, or is it a feature?
> 

Well, that depends...

If you don't have colour management set up, then it is a feature.

If you do have colour management set up, then it is a bug. Colour
management in 1.2.1 for images is *completely* borked.

(Yes, devs, I really can back this one up - The byte ordering of
channels expected by little CMS is *NOT* the same as the byte ordering
used by the QT QColor class. Look at the code and you will see that the
colour transforms assume that they are the same. Remember ages ago when
I said that I didn't understand why solid colours where proofed to
screen differently to images? This is why. As I said before patches and
bug reports are coming soon.)


cheers

dc


-- 
David Purton
dcpurton at chariot.net.au
 
For the eyes of the LORD range throughout the earth to
strengthen those whose hearts are fully committed to him.
                                 2 Chronicles 16:9a
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