how can I animate background-image? I mean slow loading image ...

something like this ...

2. $(this).animate({ "background-image","url('image.png')" }, 500);

but this doesnt work for me ... I also tried this ... but it just show after 1s ... with no animation 

2. setTimeout(function(){
3.         $("#tblmenu").css("background-image","url('image.png')");
4.         },1000)