Following code shows how to make image maps responsive.
<div style="width:100%;">
<img id="img_ID" src="http://1.gravatar.com/avatar/a8ffc3906145930fb83c53e865a89619?s=200" usemap="#map" border="0" width="100%" alt="" />
</div>
<map id="map_ID" name="map">
<area shape="poly" coords="48,10,80,10,65,42" href="javascript:;" />
<area shape="poly" coords="30,50,62,50,46,82" href="javascript:;" />
<area shape="poly" coords="66,50,98,50,82,82" href="javascript:;" />
</map>
<script>
window.onload = function () {
var ImageMap = function (map, img) {
var n,
areas = map.getElementsByTagName('area'),
len = areas.length,
coords = [],
previousWidth = 128;
for (n = 0; n < len; n++) {
coords[n] = areas[n].coords.split(',');
}
this.resize = function () {
var n, m, clen,
x = img.offsetWidth / previousWidth;
for (n = 0; n < len; n++) {
clen = coords[n].length;
for (m = 0; m < clen; m++) {
coords[n][m] *= x;
}
areas[n].coords = coords[n].join(',');
}
previousWidth = img.offsetWidth;
return true;
};
window.onresize = this.resize;
},
imageMap = new ImageMap(document.getElementById('map_ID'), document.getElementById('img_ID'));
imageMap.resize();
return;
}
</script>