About: http://webisa.webdatacommons.org/2258728

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Horizon line is G' * (u, v, f)=0 ,where G is a gravity vector, u and v image centred coordinates and f focal length.
http://www.w3.org/ns/prov#wasQuotedFrom	stackoverflow.com