CODE EXAMPLE FOR CSS

auto zoom image css

/*HTML*/
<img src="https://c1.staticflickr.com/1/628/22240194016_50afaeb84d_k.jpg" class="full zoom" alt="" />

/*CSS*/
body *,
html * {
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
}

body {
  overflow: hidden;
}

.full {
  position: absolute;
  width: 100%;
  height: auto;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  margin: auto;
  display: block;
}

.zoom {
  animation: scale 40s linear infinite;
}
  
@keyframes scale {
  50% {
    -webkit-transform:scale(1.2);
    -moz-transform:scale(1.2);
    -ms-transform:scale(1.2);
    -o-transform:scale(1.2);
    transform:scale(1.2);
  }
}