CodeMonk3y,
может быть вы хотели так ...
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<style>
#map {
position: fixed;
left: 0; top: 0;
}
</style>
</head>
<body style="overflow: hidden">
<img id ="map" src="http://www.nationalgeographic.com/content/dam/travel/rights-exempt/Travel-2016/59-parks-52-weeks/sequoia/giant-tree-trail-sequoia-national-park.jpg"></img>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script>
$(window).on("load", function() {
var width = $("#map").width();
var height = $("#map").height();
$("body").mousemove(function(event){
var left = (width - $(window).width()) * event.pageX/$(window).width()
var top = (height - $(window).height())* event.pageY/$(window).height()
$("#map").css({left: -left, top: -top});
});
})
</script>
</body>
</html>