E' giusto cosi??Il bordo viola si visualizza sempre...
<style type="text/css">
* {margin:0;padding:0}
html, body {height:100%}
div {height:100%}
img {


display:block;
position:absolute;
top:50%;
left:50%;
margin-top:-100px;
margin-left:-100px;
background-image: url(tiab.png);
img{border: 0px;}
}