<div class="bannerbox">
<div class="banner">
<img src="img1.jpg">
</div>
</div>
.bannerbox{
position:relative;
100%;
height:675px;
overflow: hidden}
.banner{
1920px;
position:absolute;
left:50%;
margin-left:-960px;
}
<div class="bannerbox">
<div class="banner">
<img src="img1.jpg">
</div>
</div>
.bannerbox{
position:relative;
100%;
height:675px;
overflow: hidden}
.banner{
1920px;
position:absolute;
left:50%;
margin-left:-960px;
}