Early days of web browsers put clickable regions over bitmap images. Does that still work? mdn 
Part of the challenge is that the dimensions of the image have to be well registered with the coordinates used in the <area> elements of the image map.
The experiment invites an improvement to the HTML plugin to add wiki internal link behavior to <area> elements as we do with <a>.
There's related ambitions in some old tools to spatially annotate arbitrary diagrams.
pages/image-map-experiment