.caption div {
box-shadow: 0 0 5px #C8C8C8;
transition: all 0.3s ease 0s;
}
.img-circle {
border-radius: 50%;
}
.img-circle {
border-radius: 0;
}
.ratio {
background-position: center center;
background-repeat: no-repeat;
background-size: cover;
height: 0;
padding-bottom: 100%;
position: relative;
width: 100%;
}
.img-circle {
border-radius: 50%;
}
.img-responsive {
display: block;
height: auto;
max-width: 100%;
}
<div class="container">
<div class="row">
<h2>Any image, size doesn´t matter, centered and respecting ratio</h2>
</div>
<div class="row">
<div class="col-sm-2">
<p> Image in to circle</p>
<div class="ratio img-responsive img-circle" style="background-image: url(http://image.com/img/trovacamporella-fiat500.png);"></div>
<p> Image in to circle with link</p>
<a href="http://trovacamporall.com" class="ratio img-responsive img-circle" style="background-image: url(http://image.com/img/trovacamporella-fiat500.png);"></a>
</div>
</div>
</div>