未知宽高图片水平垂直居中在div

<BODY>
<div class="box">
<span class="car"></span>
<img src="data:images/01.jpg" title="car" />
</div>
</BODY>

.box {
width: 100%;
overflow: hidden;
text-align: center;
/*font-size: 0;*/
border: 1px solid #000000;
margin: 50px auto;
}
.box .car {
display: inline-block;
width: 0;
height: 100%;
font-size: 0;
line-height: 0;
vertical-align: middle;
}
.box img {
vertical-align: middle;
}

参考：http://linxz.github.io/tianyizone/middle_02.html