Face movement analysis with MS Kinect

This experimental study investigated possibility of face symmetry and symmetric face movements evaluation using MS Kinects HD face tracking. The main motivation for this research is facial paralysis or partial loss of muscle control caused by stroke. Evaluation of face symmetry can be used as an indicator of positive improvement of such disability. Precision of face model acquisition of MS Kinect v2 was estimated and two data sets of four facial exercises were recorded. Differences between data sets are evaluated with comparison of left part of face to the right one, with comparison of base frame with face at rest to frames during exercises, and with changes of angles of symmetric points on face. Results show significant differences between both sets, even though face tracking is affected by lightning, distance from camera and position angle of recorded person in view of sensor. Best results are achieved when comparing changes of angles (up to 6°) and differences of in symmetry of face (56% total sym­metry in normal set to 13% symmetry in simulated set).