Tamanho da imagem de cabeçalho no tema Newsworthy

O meu arquivo functions.php é esse:

<?php
/**
* Sets up the theme and provides some helper functions. Some helper functions
* are used in the theme as custom template tags. Others are attached to action and
* filter hooks in WordPress to change core functionality.
*
*
* For more information on hooks, actions, and filters, see http://codex.wordpress.org/Plugin_API.
*/

/**
* Set the content width based on the theme’s design and stylesheet.
*
* @package Newsworthy
*/
if ( ! isset( $content_width ) )
$content_width = 585; /* pixels */

/*
* Load Jetpack compatibility file.
*/
require( get_template_directory() . ‘/inc/jetpack.php’ );

if ( ! function_exists( ‘newsworthy_setup’ ) ):
/**
* Sets up theme defaults and registers support for various WordPress features.
*/
function newsworthy_setup() {

/**
* Make theme available for translation
* Translations can be filed in the /languages/ directory
* If you’re building a theme based on _s, use a find and replace
* to change ‘_s’ to the name of your theme in all the template files
*/
load_theme_textdomain( ‘newsworthy’, get_template_directory() . ‘/languages’ );

/**
* Customizer additions
*/
require( get_template_directory() . ‘/inc/customizer.php’ );

/**
* Custom template tags for this theme.
*/
require( get_template_directory() . ‘/inc/template-tags.php’ );

/**
* Add default posts and comments RSS feed links to head
*/
add_theme_support( ‘automatic-feed-links’ );

/**
* This theme uses wp_nav_menu() in one location.
*/
register_nav_menus( array(
‘primary’ => __( ‘Primary Menu’, ‘newsworthy’ ),
) );

/**
* Visual editor
*/
add_editor_style();

/**
* Post formats
*/
add_theme_support( ‘post-formats’,
array(
‘aside’,
‘gallery’,
‘link’,
‘image’,
‘quote’,
‘status’,
‘video’,
‘audio’,
‘chat’
)
);

/**
* Enable support for Social Links
*/
add_theme_support( ‘social-links’, array( ‘facebook’, ‘twitter’, ‘linkedin’, ‘tumblr’ ) );
}
endif;
add_action( ‘after_setup_theme’, ‘newsworthy_setup’ );

/**
* Custom background
*/
$newsworthy_custom_background = array(
‘default-color’ => ‘f2f2f2’,
);
add_theme_support( ‘custom-background’, $newsworthy_custom_background );

/**
* Register widgetized area and update sidebar with default widgets
*/
function newsworthy_widgets_init() {
register_sidebar( array(
‘name’ => __( ‘Sidebar’, ‘newsworthy’ ),
‘id’ => ‘sidebar’,
‘before_widget’ => ‘<aside id=”%1$s” class=”widget %2$s”>’,
‘after_widget’ => “</aside>”,
‘before_title’ => ‘<h2 class=”widget-title”>’,
‘after_title’ => ‘</h2>’,
) );

}
add_action( ‘widgets_init’, ‘newsworthy_widgets_init’ );

/**
* Adds custom classes to the array of body classes.
*/
function newsworthy_body_classes( $classes ) {
if ( ! is_multi_author() ) {
$classes[] = ‘single-author’;
}

return $classes;
}
add_filter( ‘body_class’, ‘newsworthy_body_classes’ );

/**
* Returns true if a blog has more than 1 category
*/
function newsworthy_categorized_blog() {
if ( false === ( $all_the_cool_cats = get_transient( ‘all_the_cool_cats’ ) ) ) {
// Create an array of all the categories that are attached to posts
$all_the_cool_cats = get_categories( array(
‘hide_empty’ => 1,
) );

// Count the number of categories that are attached to the posts
$all_the_cool_cats = count( $all_the_cool_cats );

set_transient( ‘all_the_cool_cats’, $all_the_cool_cats );
}

if ( ‘1’ != $all_the_cool_cats ) {
// This blog has more than 1 category so newsworthy_categorized_blog should return true
return true;
} else {
// This blog has only 1 category so newsworthy_categorized_blog should return false
return false;
}
}

/**
* Flush out the transients used in newsworthy_categorized_blog
*/
function newsworthy_category_transient_flusher() {
// Like, beat it. Dig?
delete_transient( ‘all_the_cool_cats’ );
}
add_action( ‘edit_category’, ‘newsworthy_category_transient_flusher’ );
add_action( ‘save_post’, ‘newsworthy_category_transient_flusher’ );

/**
* Enqueue Google Fonts
*/
function newsworthy_fonts() {

$protocol = is_ssl() ? ‘https’ : ‘http’;

/* translators: If there are characters in your language that are not supported
by Carrois Gothic, translate this to ‘off’. Do not translate into your own language. */

if ( ‘off’ !== _x( ‘on’, ‘Oswald font: on or off’, ‘newsworthy’ ) ) {
wp_register_style( ‘newsworthy-oswald’, “$protocol://fonts.googleapis.com/css?family=Oswald:400,700,300” );
}
}
add_action( ‘init’, ‘newsworthy_fonts’ );

/**
* Enqueue font styles in custom header admin
*/
function newsworthy_admin_fonts( $hook_suffix ) {

if ( ‘appearance_page_custom-header’ != $hook_suffix )
return;

wp_enqueue_style( ‘newsworthy-oswald’ );

}
add_action( ‘admin_enqueue_scripts’, ‘newsworthy_admin_fonts’ );

/**
* Enqueue scripts and styles
*/
function newsworthy_scripts() {
wp_enqueue_style( ‘style’, get_stylesheet_uri() );
wp_enqueue_style( ‘newsworthy-oswald’ );

wp_enqueue_script( ‘navigation’, get_template_directory_uri() . ‘/js/navigation.js’, array( ‘jquery’ ), ‘20120206’, true );

wp_enqueue_script( ‘skip-link-focus-fix’, get_template_directory_uri() . ‘/js/skip-link-focus-fix.js’, array(), ‘20130115’, true );

if ( is_singular() && comments_open() && get_option( ‘thread_comments’ ) ) {
wp_enqueue_script( ‘comment-reply’ );
}

if ( is_singular() && wp_attachment_is_image() ) {
wp_enqueue_script( ‘keyboard-image-navigation’, get_template_directory_uri() . ‘/js/keyboard-image-navigation.js’, array( ‘jquery’ ), ‘20120202’ );
}
}
add_action( ‘wp_enqueue_scripts’, ‘newsworthy_scripts’ );

/**
* Implement the Custom Header feature
*/
require( get_template_directory() . ‘/inc/custom-header.php’ );

// updater for WordPress.com themes
if ( is_admin() )
include dirname( __FILE__ ) . ‘/inc/updater.php’;

Nele eu não encontrei o trecho específico do HEADER, que seria este:

$args = array(
‘width’ => 980,
‘height’ => 60,
‘default-image’ => get_template_directory_uri() . ‘/images/header.jpg’,
);
add_theme_support( ‘custom-header’, $args );

Basta eu incluir esse código, adaptando para as minhas medidas, que funcionará?