<http://schema.org/description>
"When you're using Google for search, one of the cooler features is dragging or uploading an image into the search box and letting the company's computer vision technology find results ..."^^<http://www.w3.org/2001/XMLSchema#string>
<http://thenextweb.com/google/2012/07/02/google-improves-search-by-image-now-includes-knowledge-graph-in-results/>