post-processing, HTML <map>'s, element geometry

hi there, matplotlib is great!

i want to create bar-charts, save to PNG and produce an HTML map to be
used over the PNG. something like this:

<map name="a">
<area shape="rect" coords="20,90,25,30" href="1.html">
<area shape="rect" coords="40,60,45,30" href="2.html">
<img src="a.png" usemap="#a">

so that when the user clicks on bar1 or bar2 of the chart, the appropriate
URL is loaded.

is there a way to get the coordinates of the bar from matlab, or do i have
to do some optical-chart-recognition? (or make my own little charting