<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<div class="container">
<div class="row">
<img src="http://lorempixel.com/400/400/" />
</div>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/gsap/1.18.4/TweenMax.min.js"></script>
<script>
var docElement = document.documentElement;
var tl = new TimelineMax({ repeat: -1, yoyo: true, onUpdate: updateRoot });
var cs = getComputedStyle(docElement, null);
var blur = {
value: cs.getPropertyValue("--blur")
};
tl.to(blur, 2, { value: "25px" });
function updateRoot() {
docElement.style.setProperty("--blur", blur.value);
}
</script>
