从平铺img创建单个img

如何从如下平铺结构创建单个图像:

+-----+-----+-----+
|tile1|tile2|tile3|
+-----+-----+-----+

<div>        
  <div>    
    <img> tile 1
  </div>  
</div>
<div>        
  <div>    
    <img> tile 2
  </div>  
</div>
<div>        
  <div>    
    <img>  tile 3
  </div>  
</div>

详情如下:

<div style="position: absolute; left: -256px; top: -256px; width: 256px; height: 256px;">
    <div style="position: absolute; left: 0px; top: 0px;">
         <img src="tile1.png" style="width: 256px; height: 256px;">
    </div>
</div>
<div style="position: absolute; left: 0px; top: -256px; width: 256px; height: 256px;">
    <div style="position: absolute; left: 0px; top: 0px;">
         <img src="tile2.png" style="width: 256px; height: 256px;">
    </div>
</div>
....