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RE: imagemaps

From: Jim Thatcher <thatch@attglobal.net>
Date: Thu, 15 Mar 2001 08:52:01 -0600
To: "Bailey, Bruce" <Bruce_Bailey@ed.gov>
Cc: w3c-wai-gl@w3.org
Message-id: <NDBBKJDAKKEJDCICIODLKENACOAA.thatch@attglobal.net>
RE: imagemapsPoint of information - Isn't the map at mapblast.com an image
button, not an image map? What am I missing?

Jim
jim@jimthatcher.com
Accessibility Consulting
http://jimthatcher.com
512-306-0931

  -----Original Message-----
  From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org]On
Behalf Of Bailey, Bruce
  Sent: Thursday, March 15, 2001 7:43 AM
  To: 'Charles McCathieNevile'
  Cc: w3c-wai-gl@w3.org
  Subject: RE: imagemaps


  Dear Charles,
  Thanks for thinking of this common counter example.
  Services like MapBlast and the like can be quite accessible.  The text
directions are, for example, quite good.
  But what about the maps themselves -- where EVERY pixel is different hot
spot?
  Can such a service achieve Single-A compliance or better?  (Without
resorting to SVG as Charles suggests.)  Where does WCAG 1.0 make allowances
for such things?  Is there not a way to eliminate all the extra verbiage
about server side images maps, but still allow these kind of tools?

  Section 508, to my mind, gets around this problem with the allowances for
equivalent facilitation.  Also, in the software portion, it discusses how
keyboard access is only needed for textually oriented functions.  This
means, for example, that paint programs are not prohibited by 508 -- even
though such applications are not useful to a blind person.  Is there a
similar escape clause in the WCAG?

  -- Bruce

    ----------
    From:   Charles McCathieNevile
    Sent:   Thursday, March 15, 2001 8:01 AM
    To:     Bailey, Bruce
    Cc:     w3c-wai-gl@w3.org; 'jim@jimthatcher.com'
    Subject:        RE: imagemaps

    Although a server side map is just a collection of points, so in theory
could
    be broken into a big pile of 1x1 squares, there are practical reasons
for
    having them in some cases.

    For example, mapping applications will generate a map on the fly from a
much
    larger store of information, send it down, and then when a point is
selected
    on the map generate a new one based on that point. The practical value
of a
    client-side image map is in part that it can have alternatives
associated
    with the destination of each hotspot. But in fact is not always very
easy to
    provide useful alternatives - for example in the mapping scenario.

    An alternative technique for doing this might be as follows:

    Use SVG to create the maps. Make each street a "hot" object, with the
default
    activation behaviour to get a new map based on that point. The basic
    algorithm can be based on the client side on DOM changes or animations
to a
    use element. On the server side you could implement the same algorithms,
but
    you might choose to use a different processing language (or not...)

    Charles McCN
Received on Thursday, 15 March 2001 09:56:54 GMT

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