Edit in JSFiddle

<div id="background-image"></div>
#background-image {
  background: url('http://images.freeimages.com/images/large-previews/08a/street-by-night-1225351.jpg');
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 0;
  min-height: 100%;
  height: auto;
}
$(document).ready(function() {
  var pixelToMove = 50;
  $("#background-image").mousemove(function(e) {
    var width = $(this).innerWidth();
    var height = $(this).innerHeight();
    var newValueX = (e.pageX / width) * pixelToMove;
    var newValueY = (e.pageY / height) * pixelToMove;
    $(this).css('background-position', newValueX + '%' + ' ' + newValueY + '%');
  });
});