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Re: Reading upper-level Unicode glyphs in PDF

for

From: Jukka K. Korpela
Date: Sep 8, 2009 3:00PM

ejp10 wrote:

> Welcome to my favorite black hole in the standards.

There's really no hole, regarding the accessibility of "special" characters.
It's just unstandardized. (There are really no _standards_ on accessibility,
unlike on character code, and the various "recommendations" and "guidelines"
are mostly very silent about "special" character issues.)

> For the record,
> the problem isn't Unicode, but lack of Unicode support on JAWS.

It's far more than that. Please remember that the vast majority of people
are not using JAWS and still have accessibility problems of different kinds.

The four basic accessibility issues with any "special" character (a very
relative concept of course - to me, "ä" is not special at all - it is a very
common letter -, to you it might be) are:
1) the user does not see or otherwise perceive the character at all (e.g.,
due to font problems)
2) the user sees a wrong character (or hears a wrong name etc.)
3) the user does not understand the character
4) the user misunderstands the character.

For the great majority of characters and people, item 3 is the real problem.

> For
> low vision audiences, Unicode does provide significant accessibility
> advantages over, for example, images because text can be zoomed and
> not pixellate.

Read "use of text characters" for "Unicode".

> For JAWS, it should be possible to add .sbl files which match things
> like Unicode 2126 to an actual Unicode name like "Ohm".

The actual Unicode name is OHM SIGN, and Unicode names are, in general,
identifiers assigned to characters. They are not supposed to be generally
useful names, and some of them are outright misleading, wrong, or absurd
(there's even a Unicode Consortium document on this) - and they will never
be changed. Moreover, though most of them are at least somewhat
understandable when used as a name, this really applies to English language
only.

The correct reading of the OHM SIGN in context depends on the context and on
the language. You cannot really guess how it should be read in Finnish, for
example... and it should almost never be read as something like "Ohm sign"
(name of the character) but rather as "Ohms", "Ohm", "ohmia" etc. (name of
unit in sentence context).

> Another thing to be careful of is to NOT use the Microsoft Word Insert
> palette. That often inserts non-Unicode material.

I'd say "sometimes" rather than "often". If you don't use Wingdings or other
fancy fonts and don't insert special controls (like line break controls),
you normally get a real Unicode character.

--
Yucca, http://www.cs.tut.fi/~jkorpela/