http://sridharkatakam.com/overlaying-text-background-image-minimum-pro-part-2/

gistfile1.php

genesis_register_sidebar( array(
	'id'          => 'home-bkgrd-image',
	'name'        => __( 'Home Background Image', 'minimum' ),
	'description' => __( 'Widgets placed here will appear on top of home background image.', 'minimum' ),
) );

//* Add overlay div below home slider
add_action( 'genesis_after_header', 'minimum_home_bkgrd_image_overlay', 9 );

function minimum_home_bkgrd_image_overlay() {
	if (is_home() || is_front_page()) {
		printf( '<div %s>', genesis_attr( 'home-bkgrd-image-overlay-wrapper' ) );
		genesis_structural_wrap( 'home-bkgrd-image-overlay' );

			printf( '<div %s>', genesis_attr( 'home-bkgrd-image-overlay' ) );
				genesis_widget_area( 'home-bkgrd-image' );
			echo '</div>';

		genesis_structural_wrap( 'home-bkgrd-image-overlay', 'close' );
		echo '</div>';
	}
}