#collage_container{
    height:100%;
    background: url(images/collage.jpg);
    background-size:cover;
    background-position:center;
    background-attachment:fixed;
    background-repeat:no-repeat
    }

<div id="collage_container">
    <div class="logo"><img src="images/mypinoy_logo.png"></div>
    <div class="tagline"><img src="images/tagline.png" /></div>
</div>