[OSM-talk] SVG to PDF

[Simon Hewison]

Jochen Topf wrote:
> Hi!
> 
> Is anybody aware of any Open Source software which turns SVG into PDF
> keeping the data as vectors and not rasterizing it? Inkscape, rsvg,
> batik all rasterize the image and then put it into the PS/PDF. You'll see
> that if you zoom in. But PDF is a vector format, so it could be done
> better. This is obviously difficult in cases where you use the more
> advances features of SVG like filtering, but in our case with the maps it
> should work just fine.
> 
> If we want high quality printable maps, we need to create PDFs in some
> way and instead of re-inventing the wheel I'd rather use osmarender to
> create SVG and the PDF from there.

I think that some of the reason is that SVG natively supports transparency 
levels (alpha channels), but Postscript, and hence PDF, does not.

Adobe added transparency in Postscript 3, and PDF 1.4. A lot of people don't 
have printers/PDF viewers that support transparency.

http://en.wikipedia.org/wiki/Transparency_(graphic)

I suppose it would be easy enough to write a SVG to PDF that ignores 
transparency. It wouldn't look quite as pretty as it should.

-- 
Simon Hewison