Dr Takehiro Nagai

Dr Takehiro Nagai

Visiting Senior Fellow

Doctor of Engineering, Tokyo institute of Technology, Yokohama, Japan, Mar. 2007
Department of Information Processing
Dissertation: “Study on higher-level chromatic mechanisms underlying figure segregation by chromatic differences”
Adviser: Keiji Uchikawa, Ph.D.

M.S., Engineering, Tokyo Institute of Technology, Yokohama, Japan, May 2004.
Department of Information Processing

B.S., Engineering, Tokyo Institute of Technology, Yokohama, Japan, May, 2002,
Department of Computer Science

Medicine & Health
School of Optometry and Vision Science

Dr. Takehiro Nagai is an associate professor at Department of Information and Communications Engineering, Tokyo Institute of Technology. He is also a senior visiting scholar at the School of Optometry and Vision Science, UNSW Sydney. He obtained his Ph.D. from Tokyo Institute of Technology under the supervision of Prof. Keiji Uchikawa in 2007. Following that, he conducted post-doctoral research at UCSD with Prof. Don MacLeod. He held positions as an assistant/associate professor at Toyohashi University of Technology and Yamagata University before assuming his current position in 2018. Dr. Nagai is interested in the mechanisms of human vision, specifically the mechanisms involved in the perception of color and object surface qualities.

Employment History

  • Apr. 2007 - Mar. 2009: Post-doctoral scholar, Psychology Department, UC San Diego
  • Apr. 2009 - Mar. 2013: Assistant Professor, Department of Computer Science and Engineering, Toyohashi Tech
  • Apr. 2013 - Mar. 2018: Associate Professor, Department of Informatics, Yamagata Univ
  • Apr. 2018 - present: Associate Professor, Department of Information and Communications Engineering, Tokyo Tech
  • May 2023 - Mar. 2024 (expected): Senior Visiting Fellow, School of Optometry and Vision Science, University of New South Wales


Professional Affiliations

  • Vision Sciences Society
  • International Colour Vision Society
  • The Vision Society of Japan
  • The Color Science Association of Japan
  • Japan Society of Kansei Engineering
  • The Illuminating Engineering Institute of Japan
School of Optometry and Vision Science Level 3, Room 3.007 North Wing, Rupert Myers Building
  • Journal articles | 2023
    Cai Y; Kiyokawa H; Nagai T; Haghzare L; Arnison M; Kim J, 2023, 'Effects of specular roughness on the perception of color and opacity', Journal of the Optical Society of America A: Optics and Image Science, and Vision, 40, pp. A220 - A229, http://dx.doi.org/10.1364/JOSAA.479972
    Journal articles | 2023
    Kiyokawa H; Nagai T; Yamauchi Y; Kim J, 2023, 'The perception of translucency from surface gloss', Vision Research, 205, pp. 108140, http://dx.doi.org/10.1016/j.visres.2022.108140

  • Excellent Paper Award from the Institute of Image Information and Television Engineers (Nov, 2018)
  • Seiichi Tejima Doctoral Dissertation Award from Tokyo Institute of Technology (Feb, 2008)
  • Best Paper Award from the Vision Society of Japan (July, 2007)
  • Student Excellent Presentation Award from the Institute of Image Information and Television Engineers (Dec, 2003)

Research Aim

Dr. Nagai aims to elucidate the mechanisms of "image information processing" in the visual system. In particular, we are interested in mechanisms underlying material and color perception, which are directly related to object recognition and affections driven by such perception.

Research projects

  • Establishment of the "Shitsukan Rendering Index" for Lighting
  • The Role of Material Perception in Affective Impressions: Insights from Deep Learning and EEG
  • The Contribution of Color to Material Perception
  • Hierarchical Structure Modeling between Material Perception and Affective Impressions based on Psychophysical and Physiological Temporal Characteristics


Selected Publications

  • Hiroki Nohira, & Takehiro Nagai: Texture statistics involved in specular highlight exclusion for object lightness perception. Journal of Vision, 23(3):1, 2023.
  • Kazuto Koizumi, & Takehiro Nagai: The dominating impacts of Helmholtz-Kohlrausch effect on color-induced glossiness enhancement.  Journal of Vision, 23(1):11, 1−19, 2023.
  • Takehiro Nagai, Kana Kakuta, & Yasuki Yamauchi: Luminance dependency of perceived color shift after color contrast adaptation caused by higher-order color channels. Journal of Vision, 22(7):8, 2022.
  • Takehiro Nagai, Takuya Okada, Ken Nishino, & Natsuko Okiyama: Impact of local luminance contrast on facial skin lightness perception: a psychophysical reverse correlation study using sub-band contrast modulation noise. Vision Research, 196:108028, 2022.
  • Hiroaki Kiyokawa, Tomonori Tashiro, Yasuki Yamauchi, & Takehiro Nagai: Luminance edge is a cue for glossiness perception based on low-luminance specular components. Journal of Vision, 19(12):5, 1-22, 2019.
  • Takehiro Nagai, Toshiki Matsushima, Kowa Koida, Yusuke Tani, Michiteru Kitazaki, & Shigeki Nakauchi: Temporal properties of material categorization and material rating: visual vs non-visual material features. Vision Research, 115(PartB), 259-270, 2015.
  • Takehiro Nagai, Yuki Ono, Yusuke Tani, Kowa Koida, Michiteru Kitazaki, & Shigeki Nakauchi: Image regions contributing to perceptual translucency: A psychophysical reverse correlation study. i-Perception, 4(6), 407-428, 2013.