RE: 2.4 Proposed Modules - gpdf

[Jason White <jasonw ariel ucs unimelb edu au>]

Owen Taylor writes:
 > > 
 > > I think the issue is with the formmat, namely that PS and PDF store lit-
 > > tle (or no) structural information (eg, PS stores the position of indi-
 > > vidual letters IIRC, but not the relationship between those letters).
 > 
 > There's quite a large amount of the PDF-1.4 spec related to trying
 > to make the contents accessible. Whether 
 > 
 >  A) It is done in a useful manner

Yes it is - an entire structural tree, with elements and attributes as
in an XML or SGML document can be represented in the PDF file. There
is also provision for "text equivalents" to images etc., and various
other useful features. Together these features are known as "tagged
PDF" in the 1.4 specification.

XPDF, Ghostscript etc., don't implement these parts of the
specification yet, which is a major obstacle to the implementation of
support for PDF accessibility in Gnome or the Unix/Linux environment
in general.

 >  B) Any content generators implement it

Adobe's authoring tools support it as of the latest versions (on MS
platforms only).