[foaf-dev] RDFa for HTML imagemap accessibility and clipart?

Dan Brickley danbri at danbri.org
Sun Jan 6 13:55:25 GMT 2008

Hi folks

Digging out an old hack here, to see how it looks in the light of RDFa.

I'd like someone to explain to me how current RDFa could be used to 
extract info from imagemap markup. I'll try to find out myself using the 
.js parser, but I'm not currently intimate with the subtle details of 
the spec.

HTML has a somewhat neglected notation for describing regions of images, 
and associating them with links. Here's a picture of me markup up in 
this way, using YokMap, a Shareware MacOSX imagemap editor:


The markup is small enough I'll include it inline here:

<map name="da8bb51_b" id="da8bb51_b">
<area  shape="POLY"

   href="http://danbri.org/" />
</map> <img  src="2169955372_503da8bb51_b.jpg"  width="1024" 
height="770" usemap="#da8bb51_b" />

A few years ago, both in the FOAF project and as part of the EU 
SWAD-Europe project some of us were experimenting with using this as 
metadata in RDF, and as something that can be transformed and visually 
presented with SVG.

The core imagemap markup just gives us a slot for an href on the area; 
here I've put my homepage URI (also same as my OpenID URI). BTW I have 
no idea what the current XHTML 2 and WhatWG/HTML5 folks have planned for 
these elements. But I think this kind of markup has a lot of potential 
for making images on the Web more automation friendly.

Here is a very basic XSLT by Max Froumentin that transforms
the above markup into SVG, and shades out the background into pink:


SVG output is here: http://danbri.org/2008/imagemap/_output.svg

Here's an old screengrab of a big jumble of similar image fragments, 
from RDF/SVG image annotation tools that Jim Ley. Also here's a 
screenshot of Jim's SVG annotator in action, showing that such metadata 
can be created easily in zero-install Web apps.

Right now I'm not sure exactly what triples we should be aiming for. I'd 
like a way to say,

"this area of the image depicts the person who is the primaryTopic of 

There were some #swig collaborations around this vocab a while back (see 
links below), though I don't think the final vocab ever got uploaded to 
http://www.w3.org/2004/02/image-regions  ... in a sense it doesn't 
matter here, since if RDFa can be used freely with this markup, we 
should be able to pick whichever RDF vocab is currently fashionable?

Any help RDFa-ifying http://danbri.org/2008/imagemap/real.html would be 
much appreciated...

Why am I digging this up? Partly because it's time to revisit the 
codepiction project, as a way of encouraging social-network-interop folk 
to consider "evidence-based" as well as claim-based models. But that's 
another story...



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