DIV半透明，内层不受影响的代码

<div style=" background:rgba(0, 0, 0, 0.1)"><br />
        <img src="http://img.17cosplay.com/uploadImgs/Carousel/2b21a700-47d6-423b-94a4-746a74323517.JPG" width="100" />
    </div>