在线运行代码 - 菜鸟教程

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"> 
<title>菜鸟教程(cainiaoplay.com)</title>
<style>.container {
    position: relative;
}

.center {
    position: absolute;
    left: 0;
    top: 50%;
    width: 100%;
    text-align: center;
    font-size: 18px;
	margin-top:-9px;
}

img { 
    width: 100%;
    height: auto;
    opacity: 0.3;
}
</style>
</head>
<body>

<h2>图片文本</h2>
<p>在图片中间位置添加文本信息:</p>

<div class="container">
  <img src="https://www.cainiaoplay.com/wp-content/uploads/2016/04/trolltunga.jpg" alt="Norway" width="1000" height="300">
  <div class="center">居中</div>
</div>

</body>
</html>
源代码

动行结果
