LaTeX accessibility
There is an German Diplomarbeit "Accessibility-Erhöhung von LaTeX-Dokumenten" by Babett Schalitz, written in German language in the year 2007. In English the title is something like: "Better accessibility for LaTeX documents". A German "Diplomarbeit" is more than a bachelor.
She wrote a prototype package accessibility.sty. Unfortunatly is the given url http://www.babs.gmxhome.de/da_pdftex/accessibility.sty yet not reachable (the url http://www.babs.gmxhome.de/download/da_pdftex/accessibility.sty works now again, so that the package is downloadable). The link to documentation (the thesis) does not work ...
This is not so much an answer to my question as it is a refinement of what needs to be done. It is too long and too heavily formatted to fit in as a comment.
The challenges in making a document accessible are
- Graphics. Graphics are inherently inaccessible as-is. One way of making a graphic accessible is to provide an adequate description of the graphic in the main body of the document. Another is to provide some alternative text (PDF and HTML both have alternative text capabilities) that somehow make the graphic accessible. While the LaTeX machinery obviously cannot provide that explanatory text, it should provide the authoring tools that enable a document author to provide an alternative explanation.
Tables. Tables can be quite accessible as-is. Whether or not they are depends on
- The mechanism used to create the table: Are the tables typeset by painting the cell contents at a certain place on the page or are they typeset using some construct? (I don't know how pdflatex generates tables. I'll look into that.)
- Whether the table is overly-tuned for sighted readers. "Professional" tables that use \multicolumn to conjoin columns, extra vertical space to separate items in a table, etc., are visually appealing but are not quite as accessible as plain old vanilla tables.
- Equations. My thought is to capture the LaTeX code used to make the equation as the alternative text. This is exactly how wikipedia.org makes the mathematical equations in some wikipedia article accessible.
- Ligatures. This one might well be the toughest challenge of all. Those ligatures on which Knuth spent so much effort come across as an unreadable character in a PDF document generated by LaTeX. The problem I see is that the treatment of ligatures is so very deep inside TeX itself. To solve the problem, words that contain ligatures need to have an ActualText tag that spells the word out as-is in text.
To the best of my knowledge, (1) Ross Moore is working on this and (2) nothing is production ready yet.
but coming soon, it will be. http://www.tug.org/tug2009/preprints/moore.pdf
Update Ross Moore's published paper is at http://www.tug.org/TUGboat/tb30-2/tb95moore.pdf