Img imitation bg-size: cover

by Symphony

HTML

<div>
<img src="https://unsplash.it/1200/800" alt="o" />
</div>

<div>
<img src="https://unsplash.it/800/1200" class="portrait" alt="o" />
</div>

CSS

div {
  position: relative;
  width: 125px;
  height: 125px;
/*overflow: hidden; delete com */
  margin: 80px 0 0 90px;
  float: left;
  outline: 2px dashed rgba(250,0,0,1)
}
div img {
  position: absolute;
  opacity: .5; /* delete com */
  left: 50%;
  top: 50%;
  width: auto;
  height: 100%;
  -webkit-transform: translate(-50%,-50%);
     -moz-transform: translate(-50%,-50%);
      -ms-transform: translate(-50%,-50%);
          transform: translate(-50%,-50%);
}
div img.portrait {
  width: 100%;
  height: auto;
}