Custom taxonomy filter for media

You can add the taxonomy parameter.

function add_image_category_filter() {
    $screen = get_current_screen();
    if ( 'upload' == $screen->id ) {
        $dropdown_options = array( 
            'taxonomy' => 'YOUR_TAXONOMY', 
            'show_option_all' => __( 'View all categories', 'iCats' ), 
            'hide_empty' => true, 
            'hierarchical' => true,
             // default is cat which wouldn't filter custom taxonomies
            'value_field'       => 'slug',
            'name'              => 'YOUR_TAXONOMY', 
            'orderby' => 'name', );
        wp_dropdown_categories( $dropdown_options );
    }
}
add_action( 'restrict_manage_posts', 'add_image_category_filter' );