div {
position: relative;
display: inline-block;
}
div:before {
content: "";
top: 0;
left: 0;
position: absolute;
height: 100%;
width: 100%;
background: -moz-linear-gradient(left, rgba(255, 255, 255, 1) 0%, rgba(255, 255, 255, 0) 49%, rgba(255, 255, 255, 1) 100%);
background: -webkit-gradient(linear, left top, right top, color-stop(0%, rgba(255, 255, 255, 1)), color-stop(49%, rgba(255, 255, 255, 0)), color-stop(100%, rgba(255, 255, 255, 1)));
background: -webkit-linear-gradient(left, rgba(255, 255, 255, 1) 0%, rgba(255, 255, 255, 0) 49%, rgba(255, 255, 255, 1) 100%);
background: -o-linear-gradient(left, rgba(255, 255, 255, 1) 0%, rgba(255, 255, 255, 0) 49%, rgba(255, 255, 255, 1) 100%);
background: -ms-linear-gradient(left, rgba(255, 255, 255, 1) 0%, rgba(255, 255, 255, 0) 49%, rgba(255, 255, 255, 1) 100%);
background: linear-gradient(to right, rgba(255, 255, 255, 1) 0%, rgba(255, 255, 255, 0) 49%, rgba(255, 255, 255, 1) 100%);
filter: progid: DXImageTransform.Microsoft.gradient(startColorstr='#ffffff', endColorstr='#ffffff', GradientType=1);
}
<div>
<img src="http://placekitten.com/g/300/300" alt="" />
</div>
-webkit-linear-gradient
,那么还有其他的方法吗? - balintpekker