Img imitation bg-size: cover

HTML

<div>
<img src="http://smoky.kiev.ua/test/img/2.jpg" alt="o" />
</div>

CSS

div {
  position: relative;
  width: 100%;
  height: 540px;
overflow: hidden;
  float: left;
  outline: 2px dashed red;
}
div img {
  position: absolute;
  left: 0;
  top: 0;
  width: auto;
  height: auto;
  -webkit-transform: translate(-50%,-50%);
     -moz-transform: translate(-50%,-50%);
      -ms-transform: translate(-50%,-50%);
          transform: translate(-20%,0%);
}