Advances in visual computing 16th International Symposium, ISVC 2021, virtual event, October 4-6, 2021 : proceedings, part II - Bebis, George; Athitsos, Vassilis; Yan, Tong; Lau, Manfred; Li, Frederick W.B; Shi, Conglei; Yuan, Xiaoru; Mousas, Christos; Bruder, Gerd 1981- (Springer, 2021)