Marker-based measurement has been used to assess human body positioning but human marker tracking has yet to make the transition from the laboratory to personal computing devices such as smartphones. A novel smartphone-based approach could use a fiducial marker system. Fiducial markers are applicable to augmented reality robotics and other applications where a camera-object pose is required and tracked. However few fiducial systems can be implemented on a mobile phone because of the processing requirements for identifying and tracking the tags in realtime. In augmented reality virtual information is shared with the real world to further enhance a person's view ...