US Patent 7912320 Method and apparatus for photographic measurement

A camera is capable of measuring distances to objects in a photographic field of view and when two such distances are measured and the included angle between their paths, a measurement standard and a vertical plane are defined. The standard is then used to measure linear dimensions of any objects within the defined vertical plane and field of view. The camera, itself, can be used, on site, to measure various objects in the field of view, or the information may be transmitted for use off site use.