<http://schema.org/image_url>
"http://media.pennlive.com/patriot-news/photo/2013/08/-0cfc03df376d0821.jpg"^^<http://www.w3.org/2001/XMLSchema#string>
<http://photos.pennlive.com/4503/gallery/cumberland_valley_opens_2013_football_training_camp_1/index.html>