Keisuke Nonaka received his Ph. D degree in Information Processing from Tokyo Institute of Technology, Japan, in 2014. He joined KDDI Corporation in 2014 and is currently a research engineer working in image and video signal processing. He was also a visiting scholar at the University of Southern California and was engaged in the research of graph signal processing in 2019. His research interests include computer vision, virtual reality, and computer-generated holograms.