I'm using child theme with twentythirteen parent. Made a directory with images in my child theme. But first removing default 2013 theme headers.
/* Add custom headers from my child theme */
add_action( 'after_setup_theme', 'childtheme_setup' );
if ( ! function_exists( 'childtheme_setup' ) ):
function childtheme_setup() {
/* Remove Default Headers */
function dr_remove_twenty_thirteen_headers(){
unregister_default_headers( array(
'star',
'diamond',
'circle'
)
);
}
add_action( 'after_setup_theme', 'dr_remove_twenty_thirteen_headers', 11 );
// Add our headers
register_default_headers( array(
'header1' => array(
'url' => get_stylesheet_directory_uri() . '/images/headers/target_head2.jpg',
//'thumbnail_url' => '%s/images/headers/circle-thumbnail.png',
'description' => _x( 'header1', 'header image description', 'twentythirteen' )
),
'header2' => array(
'url' => get_stylesheet_directory_uri() . '/images/headers/target_head1.jpg',
//'thumbnail_url' => '%s/images/headers/diamond-thumbnail.png',
'description' => _x( 'header2', 'header image description', 'twentythirteen' )
),
'header3' => array(
'url' => get_stylesheet_directory_uri() . '/images/headers/target_head0.jpg',
//'thumbnail_url' => '%s/images/headers/star-thumbnail.png',
'description' => _x( 'header3', 'header image description', 'twentythirteen' )
)
) );
}
endif;
This works on my wp 3.6. You may add more images. I have 9 :)