[Okular-devel] Re: How to best express annotations

[Albert Astals Cid]

A Dijous, 4 de novembre de 2010, Jakob Voss va escriure:
> Hi,
> 
> Apparently annotations are an issue that is still not resolved. You
> should be able to read and modify annotations that were created by other
> PDF readers, but poppler does not support it. There are also good
> reasons to store annotations separated from the original document. But
> each applications seems to have its own proprietary format to store and
> exchange annotations. I summarized some notes here:
> 
> https://github.com/nichtich/marginalia/wiki/Support-of-PDF-annotations
> 
> It looks like Okular uses its own proprietary format to express
> annotations in metadata.xml. Can you point me to any documentation of
> this format? How does it compare to the format used by other
> applications (Xournal, iAnnotate, Evernote etc.).
> 
> You could transform okular annotations to PDF annotations, and vice
> versa. The iText PDF library seems to support reading and adding PDF
> annotations. A simple sample script can be found at:
> 
> https://github.com/nichtich/marginalia
> 
> you should be able to get it running thanks to Maven, which makes
> programming in Java suck at least less. But before programming a
> converter for each custom annotation format - why not just using a
> subset of XFDF? XFDF is known for storing PDF form data, but it also
> supports PDF annotations in XML:
> 
> XML Forms Data Format Specification (XFDF) 2.0 (2007).
> http://partners.adobe.com/public/developer/en/xml/xfdf_2.0.pdf
> 
> PDF annotations are defined in chapter 8.4 of the PDF reference (2006),
> page 604-647. see
> http://www.verypdf.com/document/pdf-format-reference/pg_0604.htm
> 
> Anyway, a standard file format for Annotations which can be extracted
> from and added to PDF files, would be best.

We do know how to improve Annotation support in Okular, it's just that we do 
not have time for it.

Albert

> 
> Jakob