Only a few scientists can be proud of a real breakthrough in vision science, very few can claim significant advances in multiple aspects of our visual experience, and almost none is an acclaimed researcher in two distinct disciplines. Jan Koenderink is this unique vision scientist. In both human and machine vision, Jan Koenderink has contributed countless breakthroughs towards our understanding of the properties of receptive field profiles, of the different types of optic flow, of the surface characteristics of three-dimensional shape, and more recently of the space of color vision.

Together with his lifelong collaborator Andrea van Doorn, Jan Koenderink has approached each new problem in a humble, meticulous, and elegant way. While some papers may scare the less mathematical inclined reader, a bit of perseverance inevitably leads to the excitement of sharing with him a true insight. These insights have profoundly influenced our understanding of the functioning of the visual system. Some examples include: the structure of images seen through the lens of incremental blurring that led to the now ubiquitous wavelet representation of images, the minimal number of points and views to reconstruct a unique class of three-dimensional structures known as affine representations, the formal description of Alberti’s inventory of shapes from basic differential geometry principles, the careful description of the interplay between illumination and surface reflectance and texture, and many more. The approach of Jan Koenderink to systematically work in parallel on theoretical derivations and on psychophysical experimentations reminds us that behavioral results are uninterpretable without a theoretical framework, and that theoretical advances remain detached from reality without behavioral evidence.

Jan Koenderink trained in astronomy with Maarten Minnaert at the University of Utrecht in the Netherlands, and then in physics and mathematics. He earned his PhD in artificial intelligence and visual psychophysics with Maarten Bouman from Utrecht. He held faculty positions in Utrecht and Groningen in the Netherlands, and guest professorships from Delft University of Technology, MIT in the USA, Oxford in the UK, and KU Leuven in Belgium. Most significantly, he headed the “Physics of Man” department at the University of Utrecht for more than 30 years. Jan Koenderink has authored more than 700 original research articles and published 2 books of more than 700 pages each. He received many honors, among them a Doctor Honoris Causa in Medicine from KU Leuven, the Azriel Rosenfeld lifelong achievement award in Computer Vision, the Wolfgang Metzger award, the Alexander von Humboldt prize, and is a fellow of the Royal Netherlands Academy of Arts and Sciences.