Fade de transition d'image CSS

<!-- example -->
<head>
<style>
.fade-in-image {
  animation: fadeIn 5s;
  -webkit-animation: fadeIn 5s;
  -moz-animation: fadeIn 5s;
  -o-animation: fadeIn 5s;
  -ms-animation: fadeIn 5s;
}
@keyframes fadeIn {
  0% {opacity:0;}
  100% {opacity:1;}
}

@-moz-keyframes fadeIn {
  0% {opacity:0;}
  100% {opacity:1;}
}

@-webkit-keyframes fadeIn {
  0% {opacity:0;}
  100% {opacity:1;}
}

@-o-keyframes fadeIn {
  0% {opacity:0;}
  100% {opacity:1;}
}

@-ms-keyframes fadeIn {
  0% {opacity:0;}
  100% {opacity:1;}
}
</style>
</head>

<body>
<div class="fade-in-image">
   <img src="https://source.unsplash.com/fk4tiMlDFF0/800x600/">
</div>
</body>
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