Instead of using image maps, you could try this CSS method:
Use a transparent <div>
on top of each "image-map" part (link), and then use the CSS :hover
pseudo-class to handle the highlighting.
CSS:
#image {
position: relative;
width: 400px;
height: 100px;
background-image: url(image_map.png);
}
#map-part {
position: absolute;
top: 10px;
left: 10px;
width: 50px;
height: 50px;
background-color: transparent;
}
#map-part:hover {
background-color: yellow; /* Yellow Highlight On Hover */
opacity: 0.2;
filter: alpha(opacity=20);
}
HTML:
<div id="image">
<a id="map-part" href="http://www.example.com/"></a>
</div>
Note that this will only work for rectangular links.