如下css3代码如何变成3张以上的图片轮转？

Question

@-webkit-keyframes fadeInOut {
0% {
opacity:1;
}
25% {
opacity:0;
}
50% {
opacity: 0; 
}
75% {
opacity:1;
}
}
.anim_fade_image {
position:absolute; 
-webkit-animation-name: fadeInOut;
-webkit-animation-timing-function: ease-in-out;
-webkit-animation-iteration-count: infinite;
-webkit-animation-duration: 12s;
-webkit-animation-direction: alternate;
}