image centering with "fit" configuration

image-center-fit.css

/* Solution 1 (best) */
.wrap{
  position:relative;
}
img{
  position:abosulute;
  top:0;
  right:0;
  bottom:0;
  left:0;
  margin:auto;
}

/* Solution 2 */
.wrap{
  height:20px;
}
.wrap:after{ /* (or) wrap span{ */
  display:inline-block;
  line-height:20px;
}
img{
  line-height:20px;
  vertical-align:middle;
}