[scribus-dev] GSOC: PDF Embedding

Thach Tran tranngocthachs at gmail.com
Mon Aug 3 18:37:35 CEST 2009


Hi all,

Most of the pieces for preflighting the embedded PDFs are in place  
right now. It would be really great if you could try it out and send  
me your feedbacks/thoughts. The url for the svn repo is https://scribus.svn.sourceforge.net/svnroot/scribus/gsoc2009/pdfexport

It could detect the incompatible color usages (e.g. using DeviceRGB  
while our overall document is PDF/X, etc), transparency, non-embedded  
fonts, and too low/high resolution of images in the embedded PDFs.  
Most of the inspection code is in pdf_analyzer.cpp; and  
documentchecker.cpp will use this code to report the appropriate  
preflight errors.
One thing I'm not sure how to accomplish right now is how would I  
force the PDFs to be rasterized when there're issues. This is because  
the exporting code takes place in pdflib_core while the preflighting  
process is in another place. Any suggestion?

Regards,
Thach

On 3 Jul 2009, at 23:22, Andreas Vox wrote:
> Hi Thach!
>
> I think the first thing should be to find out what colorspaces are  
> used in
> the PDF.
> In addition it might also worth to check for used/embedded fonts and
> transparency.
>
> I suggest a new sourcefile with code that uses Podofo to read the  
> PDF and
> records:
>
> - colorspace and transparency settings (blendmode, softmask, alpha) in
> graphic states
> - use of G, g, RG, rg, K, and k operators
> - colorspaces and resolution of bitmap images
>
> This code can then used by the preflighter to warn the user about  
> issues. In
> my view that should be enough to remove the "EXPERIMENTAL" flag from  
> PDF
> embedding. We can also enforce rasterizing the PDF to fix the  
> colorspace and
> compatibility issues.
>
> Later you/we can extend the code to fix colorpace issues or embed  
> missing
> fonts. The PDF reading code may also evolve into a PDF import function
> later.
>
> /Andreas



More information about the scribus-dev mailing list