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RE: Proposal for Guideline 1.1 [definition of text]

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Wed, 25 May 2005 14:39:50 -0500
To: "'Christophe Strobbe'" <christophe.strobbe@esat.kuleuven.be>, <w3c-wai-gl@w3.org>
Message-Id: <20050525193951.3AE7260C178@m18.spamarrest.com>

You misunderstood the example.

The text is sent in character codes that are not Unicode.  Then, the user
agent paints them to the screen as pixels (as all user agents do).  The
difference is that AT can access the characters before they are painted to
the screen and, if they are Unicode, it can render them as voice etc.  if
they are not Unicode (e.g. proprietary or encrypted) and are not made
available as Unicode - then AT can do nothing with them.  

The AUTHOR is the one that decides if the user agent will make the text
available as Unicode or not.    


 -- ------------------------------ 
Gregg C Vanderheiden Ph.D. 
Professor - Ind. Engr. & BioMed Engr.
Director - Trace R & D Center 
University of Wisconsin-Madison 

-----Original Message-----
From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On Behalf
Of Christophe Strobbe
Sent: Wednesday, May 25, 2005 3:29 AM
To: w3c-wai-gl@w3.org
Subject: RE: Proposal for Guideline 1.1 [definition of text]

At 19:37 24/05/2005, Gregg Vanderheiden wrote:
Actually,   non Unicode text can be displayed visually as painted text
characters.  It can also be read by proprietary readers that render it
directly into visual characters without it being available in Unicode.  As I
understand it - this is currently done by people who publish ebooks - that
are text but cannot be 'seen' by screen readers.

According to the definitions and descriptions that I could find ([1], [2]),
"painted text" refers to bitmap images of text. So painted text is
inaccessible because it is an image format, irrespective of the character
set from which the characters are borrowed. Requiring Unicode would not make
painted text accessible because painted Unicode characters are just as
inaccessible as painted non-Unicode characters (unless you were thinking of
another definition of "painted text"). Excluding painted text from our
definition of text is easy enough: it is sufficient to point out the
difference between abstract characters on the one hand and images of text
and glyphs on the other. I have added this to the proposed definition.

      Proposed definition:
      Any sequence of characters that exist in the writing systems of
      the world's natural languages. "Character" here refers to the
      abstract meaning and/or shape, rather than a specific shape
      or glyph image. (Fonts are not collections of characters but
      collections of glyph images for the visual representation of

This distinction is not new: see Unicode's glossary [3].
I hope this clarification helps.

Best regards,


[1] http://trace.wisc.edu/docs/software_guidelines/software.htm,
by Gregg Vanderheiden, but dating back to 1994 and possibly out of date:
"Occasionally, applications will use text which has been predrawn and stored
in the program as a bit image."
[2] http://www.dsq-sds.org/_articles_pdf/2001/Spring/dsq_2001_Spring_08.pdf,
(Disability Studies Quarterly, Spring 2001): '"Painted" text refers to
letters and numbers that are placed on an image file and saved in a GIF or
JPG format.'
[3] http://www.unicode.org/glossary/

Christophe Strobbe
K.U.Leuven - Departement of Electrical Engineering - Research Group on
Document Architectures Kasteelpark Arenberg 10 - 3001 Leuven-Heverlee -
tel: +32 16 32 85 51
Received on Wednesday, 25 May 2005 19:39:56 UTC

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