Adding a full width banner image in Genesis. http://sridharkatakam.com/full-width-header-navigation-metro-pro/#comment-1263

gistfile1.php

add_action ( 'genesis_before_header', 'sk_add_full_width_banner_image' );
function sk_add_full_width_banner_image() {

	echo '<div class="banner-image"><img src="http://genesis.dev/wp-content/uploads/2013/12/header.jpg" /></div>';

}

gistfile2.css

.banner-image {
    text-align: center;
}

.banner-image img {
    width: 100%;
}