.container {
  position: relative;
  border: 1px solid #000;
  overflow: hidden;
  width: 400px;
  margin: 100px;
}
.container img {
  max-width: 100%;
  -moz-transition: all 0.5s;
  -webkit-transition: all 0.5s;
  transition: all 0.5s;
}
.container:hover img {
  -moz-transform: scale(1.2);
  -webkit-transform: scale(1.2);
  transform: scale(1.2);
}