Finds the "real" size on an image.

get-image-size.js

function getImageSize(img) {
  var i = $('<img/>')
  .css('visibility', 'hidden')
  .attr('src', $(img).attr('src'))
  .appendTo('body');
  var r = {
    width: i.width()
    , height: i.height()
  };
  i.remove();
  return r;
}