SO fiddle

Test Fiddle mainly for SO Questions

by Nick Craver

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/overcast/jquery-ui.css">
<img src="http://dummyimage.com/300x200/000/fff&text=Hover+me!" width="300" height="200" />

JavaScript

$("img").each(function() {
    $.data(this, 'size', { width: $(this).width(), height: $(this).height() });
}).hover(function() {
    $(this).stop().animate({ height: $.data(this,'size').height*1.2, 
                             width: $.data(this,'size').width*1.2 });
}, function() {
    $(this).stop().animate({ height: $.data(this,'size').height, 
                             width: $.data(this,'size').width });
});