Google Webmaster Tools is issuing me with Warnings! as I am trying to hide my images from search engines. My robots.txt has set several image folders as Disallow, however, Yoast SEO indexes these images & adds the URLs to the sitemap.xml. This creates a conflict.
How can I prevent the images being listed on the xml sitemap? I checked 'Exclude post types - media' but this had no effect. I am also using NextGen Gallery for the images.