Edit in JSFiddle

#crossfade > img { 
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0px;
    left: 0px;
    color: transparent;
    opacity: 0;
    z-index: 0;
    -webkit-backface-visibility: hidden;
    -webkit-animation: imageAnimation 30s linear infinite 0s;
    -moz-animation: imageAnimation 30s linear infinite 0s;
    -o-animation: imageAnimation 30s linear infinite 0s;
    -ms-animation: imageAnimation 30s linear infinite 0s;
    animation: imageAnimation 30s linear infinite 0s; 
}

#crossfade > img:nth-child(2)  {
    -webkit-animation-delay: 6s;
    -moz-animation-delay: 6s;
    -o-animation-delay: 6s;
    -ms-animation-delay: 6s;
    animation-delay: 6s; 
}
#crossfade > img:nth-child(3) {
    -webkit-animation-delay: 12s;
    -moz-animation-delay: 12s;
    -o-animation-delay: 12s;
    -ms-animation-delay: 12s;
    animation-delay: 12s; 
}
#crossfade > img:nth-child(4) {
    -webkit-animation-delay: 18s;
    -moz-animation-delay: 18s;
    -o-animation-delay: 18s;
    -ms-animation-delay: 18s;
    animation-delay: 18s; 
}
#crossfade > img:nth-child(5) {
    -webkit-animation-delay: 24s;
    -moz-animation-delay: 24s;
    -o-animation-delay: 24s;
    -ms-animation-delay: 24s;
    animation-delay: 24s; 
}

@-webkit-keyframes imageAnimation { 
    0% { opacity: 0;
    -webkit-animation-timing-function: ease-in; }
    8% { opacity: 1;
         -webkit-animation-timing-function: ease-out; }
    17% { opacity: 1 }
    25% { opacity: 0 }
    100% { opacity: 0 }
}

@-moz-keyframes imageAnimation { 
    0% { opacity: 0;
    -moz-animation-timing-function: ease-in; }
    8% { opacity: 1;
         -moz-animation-timing-function: ease-out; }
    17% { opacity: 1 }
    25% { opacity: 0 }
    100% { opacity: 0 }
}

@-o-keyframes imageAnimation { 
    0% { opacity: 0;
    -o-animation-timing-function: ease-in; }
    8% { opacity: 1;
         -o-animation-timing-function: ease-out; }
    17% { opacity: 1 }
    25% { opacity: 0 }
    100% { opacity: 0 }
}

@-ms-keyframes imageAnimation { 
    0% { opacity: 0;
    -ms-animation-timing-function: ease-in; }
    8% { opacity: 1;
         -ms-animation-timing-function: ease-out; }
    17% { opacity: 1 }
    25% { opacity: 0 }
    100% { opacity: 0 }
}

@keyframes imageAnimation { 
    0% { opacity: 0;
    animation-timing-function: ease-in; }
    8% { opacity: 1;
         animation-timing-function: ease-out; }
    17% { opacity: 1 }
    25% { opacity: 0 }
    100% { opacity: 0 }
}