Computer Vision Systems 12th International Conference, ICVS 2019, Thessaloniki, Greece, September 23-25, 2019, Proceedings - Tzovaras, Dimitrios; Tzovaras, Dimitrios; Giakoumis, Dimitrios; Giakoumis, Dimitrios; Vincze, Markus; Vincze, Markus; Argyros, Antonis; Argyros, Antonis (Springer International Publishing : Imprint: Springer, 2019)