<p>将图片转为灰色：</p>

​

<img src="http://static.runcodex.com/images/mix/pineapple.jpg" alt="Pineapple" width="300" height="300">

​

<p><strong>注意:</strong> IE 浏览器不支持该效果。</p>

img {

    -webkit-filter: grayscale(100%); /* Chrome, Safari, Opera */

    filter: grayscale(100%);

}