Re: PDF version 1.4 & XeTeX

[Mojca M. <moj...@gm...>]

On 5/16/07, Ethan Merritt wrote:
> On Wednesday 16 May 2007 04:47, Mojca Miklavec wrote:
> > Hello,
> >
> > I'm posting a bit weird question here. A user on the XeTeX mailing
> > list reported a problem, because XeTeX doesn't know how to interpret
> > PDF version 1.4 and thus he wasn't able to include a gnuplot-generated
> > (set term pdf) graph into his LaTeX document.
>
> PDF     Acrobat Version
> 1.3     Acrobat 4
> 1.4     Acrobat 5
> 1.5     Acrobat 6
> 1.6     Acrobat 7

I know. And now also:

1.7     Acrobat 8

But I just figured out what the problem was. The problem was not in
XeTeX, but in "ebb" for calculating bounding boxes, which uses
dvipdfmx libraries, which have
     static unsigned pdf_version = 3;
and then the program complains about "too-high pdf version", when it
just needs to calculate the bounding box. Really stupid. XeTeX
supports pdf version 1.4, but not 1.5, and pdfTeX also has problems
with newer versions.

Forget about my stupid remark. 1.4 is really something that should be
supported in any reasonable program.

> > My question is: is version 1.4 needed for some reason (advanced
> > functionality, apart from smaller PDF files)? I.e: would it still work
> > if one decided to lower the PDF version to 1.3 for example and
> > recompiled gnuplot manually?
>
> According to the PDFLib manual, PDF Version 1.4 is needed for
> transparency, pattern-fill, and shading.

PDFReference (http://www.adobe.com/devnet/pdf/pdfs/PDFReference13.pdf)
states that v1.3 supports all of them, but don't bother too much. It's
really that other tools need to be fixed, not gnuplot.

> I don't know exactly what
> would happen if you forced the compatibility level to 1.3 and then tried
> to create a plot that used these features.
>
> > (x)dvipdfm(x) will have to be improved sooner or later, and there are
> > other means to help (lower the version with acrobat etc.), but I'm
> > just curious if there are means to lower the version from withing
> > gnuplot ...
>
> If you link to a very old version of PDFlib this will happen automatically.
> If you link to a more recent version, gnuplot requests compatibility
> level 1.4 (the default would be higher than this, not lower).

Thanks again. And sorry for remarks that were really not in place.

Mojca