Server Side Image Maps (was: images / alt and image maps)

The issue of why use server side image maps came up on the GL list recently
(WCAG1 P1 checkpoints 1.2 and 9.1).
The bit about "except where the regions cannot be defined with an available
geometric shape" is, in fact, meant to apply to maps where each and every
pixel is, in effect, a different hot link.  As Jim points out, the header
graphic at King County hardly qualifies to use this techique.  We are taking
about geographic maps, such as services provided by MapBlast and the like.


From: "Jim Thatcher" <thatch@attglobal.net>
To: "Rebecca Cox" <rebecca@cwa.co.nz>, <w3c-wai-ig@w3.org>
Date: Fri, 25 May 2001 06:22:27 -0500
Message-ID: <MABBJNHDAODJNEJPGBCLGELKCCAA.thatch@attglobal.net>
Subject: RE: images / alt and image maps

Hi Rebecca,

You asked for opinons - OK! Redundant text links should be available for
server-side image maps; no reason for redundant links for client-side maps -
You must use alt text for each of the areas. 7.4.2 is preceeded with "until
user agents ...." and user agents are recognizing alt text on areas.  I
think it is wrong to also have text links when you have alt text on the
areas ... Opinion.

An example I used in the "web course"
(http://jimthatcher.com/webcourse2.htm) for me raises a very interesting
issue about image maps. The King County Washington site
(http://www.metrokc.gov/) uses a sever-side map for its primary navigation
and has equivalent text links at the bottom of the page. Section 508 would
not allow this because !
the regions (lik all regions) can be specified in a
client-side map. But using this server-side map with equivalent links at the
bottom of the page provides a skip navigation method. A dilemma!

Jim
http://jimthatcher.com
512-306-0931