header image section replacement

replace this section of header.php in 'blue splatter':

<div id="headbg-title" style="background: url(<?php header_image(); ?>); width:<?php echo HEADER_IMAGE_WIDTH; ?>px; height:<?php echo HEADER_IMAGE_HEIGHT; ?>px;">
                    <hgroup>
                <h1 id="site-title"><span><a href="<?php echo esc_url( home_url( '/' ) ); ?>" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>" rel="home"><?php bloginfo( 'name' ); ?></a></span></h1>
                <h2 id="site-description"><?php bloginfo( 'description' ); ?></h2>
                    </hgroup>
                </div>

with this section from the default header.php of Twenty Eleven:

            <hgroup>
                <h1 id="site-title"><span><a href="<?php echo esc_url( home_url( '/' ) ); ?>" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>" rel="home"><?php bloginfo( 'name' ); ?></a></span></h1>
                <h2 id="site-description"><?php bloginfo( 'description' ); ?></h2>
            </hgroup>

            <?php
                // Check to see if the header image has been removed
                $header_image = get_header_image();
                if ( $header_image ) :
                    // Compatibility with versions of WordPress prior to 3.4.
                    if ( function_exists( 'get_custom_header' ) ) {
                        // We need to figure out what the minimum width should be for our featured image.
                        // This result would be the suggested width if the theme were to implement flexible widths.
                        $header_image_width = get_theme_support( 'custom-header', 'width' );
                    } else {
                        $header_image_width = HEADER_IMAGE_WIDTH;
                    }
                    ?>
            <a href="<?php echo esc_url( home_url( '/' ) ); ?>">
                <?php
                    // The header image
                    // Check if this is a post or page, if it has a thumbnail, and if it's a big one
                    if ( is_singular() && has_post_thumbnail( $post->ID ) &&
                            ( /* $src, $width, $height */ $image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), array( $header_image_width, $header_image_width ) ) ) &&
                            $image[1] >= $header_image_width ) :
                        // Houston, we have a new header image!
                        echo get_the_post_thumbnail( $post->ID, 'post-thumbnail' );
                    else :
                        // Compatibility with versions of WordPress prior to 3.4.
                        if ( function_exists( 'get_custom_header' ) ) {
                            $header_image_width  = get_custom_header()->width;
                            $header_image_height = get_custom_header()->height;
                        } else {
                            $header_image_width  = HEADER_IMAGE_WIDTH;
                            $header_image_height = HEADER_IMAGE_HEIGHT;
                        }
                        ?>
                    <img src="<?php header_image(); ?>" width="<?php echo $header_image_width; ?>" height="<?php echo $header_image_height; ?>" alt="" />
                <?php endif; // end check for featured image or standard header ?>
            </a>
            <?php endif; // end check for removed header image ?>