html, body {
   height:100%;
   width: 100%;
   margin: 0;
   padding: 0;
   border: 0
}


img.displayed {
   position: absolute;
   top: 50%;
   left: 50%;
   width: 650px;
   height: 190px;
   margin-top: -95px; /* Half the height */
   margin-left: -325px; /* Half the width */
}