A system for determining piles comprises an interface and a processor. The interface is configured to receive an image. The processor is configured to determine one or more attributes of the image; to determine whether the image is a member of a top of a hierarchy based at least in part on the attributes. In the event it is determined that the image is a member of the top of the hierarchy: determine a set of elements of the hierarchy the image is a member of, based at least in part on the attributes and determine which of the set of entities are piles.