[Scribus] Time to defend your use of libPDF

[Andreas Vox]

> From: Calum Polwart <scribus at wittongilbert.free-online.co.uk>
> Subject: [Scribus] Time to defend your use of libPDF
> To: "scribus at nashi.altmuehlnet.de" <scribus at nashi.altmuehlnet.de>
> Message-ID: <1138215397.32722.137.camel at localhost.localdomain>
> Content-Type: text/plain; charset="us-ascii"
>
> I have been trying to sort a problem manipulating scribus pdf's with
> mutlivalent where I get a slight margin between the two A5 pages when
> the are tiled onto A4.
>
> The response I get from Tom Phelpps who wrote multivalent seems to
> critcise Scribus PDF's in two ways:
>
> 1. ...
>
> 2. He says the following:
>
> "By the way, the PDF generator, Libpdf by Scribus, generates terrible
> PDF.  It
> is extremely inefficient and redundant, and has outright errors in the
> font
> widths and Trimbox."
>
> But I thought Scribus were always saying that their PDF was fully
> standards compliant??  What errors in the font widths? Could this be 
> why
> my Arial Font 'l' apear on screen like fat 'l's but print OK? (Don't
> know what a trim box is!)
>
> So here is your opportunity to defend yourselves...  (You could open
> with ... at least our software is opensource!)


Well, terrible PDF can still be standards compliant :-)

The Scribus PDF code (I rather not say libPDF because there's an 
independent product of that name) positions each char separately, which 
can be considered
inefficient and redundant, but has the advantage that the printout 
looks *exactly* as on
screen (minus aligning errors due to low screen resolution).
The Scribus PDF output was tested numerously by preflight tools and 
never crashes a print job at a commercial printer. That is our main 
target. We know that the resulting PDF is not very
good for Web display or postprocessing by other tools like Multivalent. 
We might implement an option for "nice" PDF some time, but right now 
that hasn't any priority for us.

If there are outright errors in the widths we would very much 
appreciate a bug report with
an example.

The fat 'I's in your Arial in screen are most likely due to the missing 
hinting. Scribus turns off
hinting in all fonts since it want's to achieve 1:1 screen and print 
correspondence. This sometimes looks bad on screen, but should be 
alright when you zoom in (yes, that means we will *not* fix it :-) )

/Andreas