【children_parent】
<!DOCTYPE html>
<html>
<head>
<style type='text/css'>
.image {
position: relative;
}
.wrapper {
position: absolute;
top: 50%;
left: 0;
}
h2 {
margin: 0;
padding: 0;
}
</style>
</head>
<body>
<div class="image">
<img src="http://www.w3cschool.cn/style/download.png" />
<div class="wrapper">
<h2>Title</h2>
</div>
</div>
</body>
</html>
