$("div.container").mousemove(function(e){
var avatarImg = $("#avatar");
var avatarPosition = avatarImg.offset();
var mousePositionX = e.pageX - avatarPosition.left;
var mousePositionY = e.pageY - avatarPosition.top;
var overlayNewHeight = avatarImg.height() - mousePositionY;
$("div.overlay").height(overlayNewHeight);
});
$("div.container").mouseleave(function(){
$("div.overlay").height(0);
});
.container {
position: relative;
width: 50%;
margin-left: 100px;
margin-top: 100px;
border: black solid 1px;
}
#avatar {
display: block;
width: 100%;
height: auto;
}
.overlay {
position: absolute;
bottom: 0;
left: 0;
right: 0;
background-color: #008CBA;
overflow: hidden;
width: 100%;
height: 0;
transition: .5s ease;
}
.text {
color: white;
font-size: 20px;
position: absolute;
top: 50%;
left: 50%;
-webkit-transform: translate(-50%, -50%);
-ms-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
<body>
<h2>Slide in Overlay from the Bottom</h2>
<p>Hover over the image to see the effect.</p>
<div class="container">
<img src="https://i.imgur.com/I80W1Q0.png" alt="Avatar" class="image" id="avatar">
<div class="overlay">
<div class="text">Hello World</div>
</div>
</div>
<script src="http://code.jquery.com/jquery-1.12.4.min.js"></script>
</body>
