function plt_hide_smart_image_resize_menus() {
//Hide the "Tools → Scheduled Actions" menu.
remove_submenu_page('tools.php', 'action-scheduler');
//Hide the "Settings → Smart Image Resize" menu.
remove_submenu_page('options-general.php', 'wp-smart-image-resize');
}
add_action('admin_menu', 'plt_hide_smart_image_resize_menus', 11);