[pdftex] making pdf document accessible using LaTeX

Neil Soiffer NeilS at dessci.com
Fri Nov 16 21:50:27 CET 2007


I like the name "serendiPDF"... too bad there wasn't a way to squeeze an "e" 
sound on the end :-)

>From your tug article (www.tug.org/TUGboat/Articles/tb23-1/moore.pdf), it 
sounds like you had multiple reasons for developing serendiPDF.  One was for 
teaching TeX in some sense (TeX by example) and another was for searching 
within the document.   Have you had any feedback on either?

If wasn't clear from your article how the TeX is represented in the PDF. 
The PDF isn't tagged, so I'd guess they are annotations.  I realize that 
accessibility wasn't your goal, but putting them in as Alt Tags would have 
made the document much more readable/intelligible to someone using a screen 
reader.  It would also mean that search engines would likely find the TeX. 
I'm sure someone will correct me if I'm wrong, but I don't think search 
engines look at PDF annotations.

In your paper you described a macro package that did some pretty clever 
hacks to insert the TeX.  If you didn't need to creates forms/targets for 
the JavaScript and just wanted to create Alt tags with the TeX, it seems 
that it would have been simpler to get them into the PDF -- you wouldn't 
need to the measuring in that case.  Do you think it is something that 
pdftex itself could/should do, or do you think adding tags is best left to a 
macro package?  Is it something you could do to your macro package?  If you 
do add the Alt tag, make sure you add a "Formula" tag around the math parts 
also -- both the PDF spec and draft for PDF/UA say it should be used.

Standing up on my soapbox...
Being someone working on accessibility, I obviously think that TeX should 
produce something that is accessible.  But I'm not alone.  Many governments 
and lots of Universities are developing accessibility requirements for 
electronic material on their web sites.  This was the chief motivating 
factor for AIIM to start up a standards effort.

I hope the developers on this list make accessibility of the PDF a priority 
by producing tagged PDF that includes the TeX, or better yet, a MathML 
equivalent for the math parts of documents.  Sadly, accessibility is an area 
where pdftex is behind where it should be.

Neil Soiffer
Senior Scientist
Design Science, Inc.
~ Makers of Equation Editor, MathType, MathPlayer and MathFlow ~

----- Original Message ----- 
From: "Ross Moore" <ross at ics.mq.edu.au>
To: "Neil Soiffer" <NeilS at dessci.com>
Cc: <pdftex at tug.org>
Sent: Wednesday, November 14, 2007 12:19 PM
Subject: Re: [pdftex] making pdf document accessible using LaTeX

> Hi Neil,
> On 15/11/2007, at 5:39 AM, Neil Soiffer wrote:
>>> By the way, I have been pointed to a developing NISO standard for
>>> accessible maths, that would be similar to this with MathML, if I
>>> understood well. A variation of Design Science's MathPlayer would
>>> have
>>> been able to read aloud such a PDF, including the maths read not
>>> as ASCII
>>> source, but as real maths.
>> I think the standard you are referring to is the DAISY+MathML
>> spec.  It is
>> available at
>> www.daisy.org/projects/mathml
>> Another effort people might be interested in is PDF/UA (Universal
>> Access).
>> This AIIM committee that is working on developing an ISO standard for
>> accessible PDF. See www.aiim.org/standards.asp?ID=27861.  Part of
>> that work
>> involves making sure that math in PDF is accessible.  It does this by
>> tagging the math with MathML.
> Back in 2002, I developed a method to include the TeX source of
> mathematics
> as popup text-fields in a PDF, generated by pdfLaTeX. As the mouse
> tracks over
> the displayed mathematics, a button appears to toggle show/hide of
> the field.
> Furthermore, the fields are searchable, so I added a simple search
> widget,
> and Javascript methods to implement searching.
> I called this technique  serendiPDF , and showed an example at TUG
> 2002, India.
> The attached PDF is the example that I used there.

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