Mouse over of arbitrary shapes

I can think of a number of ways do detect if the mouse if over (or
clicking on, etc) a arbitrary shaped bitmapped image (say, some sprite
where we want pixel-perfect click detection, not an enclosing
rectangle) , such as some kind of array with a mask in it, individual
lines of the sprite split into tiny rectangles, doing it all on the
server side via an XML request, but I wondered if anyone could offer
their experience or thoughts on the "best" way to do this that doesn't
eat too much client or server resources.

amaccormack@gmail.com wrote:Hi,

What about the good old imagemap?
Google 'imagemap', and you'll find a lot of resources.

You can make arbitrary shapes in it, and define also your JavaScript
handlers.

Here is a quick starters guide:
http://www.w3schools.com/tags/tag_map.asp

Of course you can also homecook your own routine, based on the x and y
position of the mouse over the image, but why reinvent the wheel?

Regards,
Erwin Moller