Re: pdf images in html export

[Andreas Leha <andreas.leha@med.uni-goettingen.de>]

Hi Rainer,

Rainer M Krug <Rainer@krugs.de> writes:
> Andreas Leha <andreas.leha@med.uni-goettingen.de> writes:
>
>> Hi Marco,
>>
>> Marco Wahl <marcowahlsoft@gmail.com> writes:
>>> Andreas Leha <andreas.leha@med.uni-goettingen.de> writes:
>>>
>>>> how would I export an org file containing
>>>>
>>>>   [[file:./myimage.pdf]]
>>>>
>>>> to html so that a say png version myimage.pdf is inlined in the html
>>>> which links to the pdf?
>>>>
>>>> I guess it should be possible to run imagemagick on all pdf links during
>>>> export somehow.
>>>      
>>> You could introduce a relation of the pdf-filenames to the respective
>>> thumb-filenames e.g. by using the suffix '_thumb'.  Before the export
>>> the conversion tool would create the thumbs.
>>>
>>> The org-file could reference the data as
>>>
>>> [[file:./myimage.pdf][file:myimage_thumb.png]]
>>>
>>> See the info page (info "(org)Images in HTML export")?
>>>
>>> Untested.  I just accidentially browsed that info page yesterday.
>>>
>>>
>>
>> Thanks for your thoughts.  I would like to automate all of that.  So, I
>> guess the first question is where to put code that would trigger the
>> conversion and how to best detect links to pdfs.
>
> Well - this is coming again and again - but no solution out of the
> box. There are effectively two approaches:
>
> 1) Macro to change properties according to backend used.  
>
> One usage is changing the file name extension according to the
> backend. This is implemented as a simplified macro below. This could
> be done by using ~(by-backend (html "graph.png") (latex "graph.pdf") (t "graph.pdf"))~
>  
> See [[http://orgmode.org/worg/org-contrib/babel/languages/ob-doc-LaTeX.html#sec-4-3][work section ob-doc-LaTeX]] for details.
>
> #+begin_src emacs-lisp
>   (setq org-babel-latex-htlatex "htlatex")
>   (defmacro rmk-by-backend (&rest body)
>     `(case (if (boundp 'backend) (org-export-backend-name backend) nil) ,@body))
> #+end_src
>
> 2) To use svg image format, which is supported by both (although has
>    it's drawbacks: slow rendering of the html, need to run external programs upon compilation)
>
> So the first might be the modst feasible option.
>

Thanks for this.  I am aware of how to *produce* graphics in different
formats for different export backends.  I use your first approach,
which I think is the better solution.

Here, I am after a solution, that works on images that are not produced
but merely included via [[file:./some.pdf]].

I think there should be the possibility to include these into html (and
odt) export without any user interaction.  So, I
- do not want to write a source block just to produce the by-backend image
- do not want to change the link manually
- do not want to run the converter manually

I am pretty sure this should be achievable with standard orgmode tools
(like filters, export hooks, or anything).

Since 'this is coming again and again' it seems a non-esoteric task.
And as there is 'no solution out of the box', I assume(d) that somebody has
written these filters already.

Regards,
Andreas