Hiroaki Santo, Graduate School of Information Science and Technology, Osaka University
Light Structure from Pin Motion
We present a practical method for the geometric calibration of point light sources which is based on a Lambertian plane and small needle pins at unknown positions that cast shadows on the plane. We show an interesting mathematical connection between pinhole cameras and point light sources which, combined with bundle adjustment, enables us to simultaneously estimate the point light position and the pin positions only from the observed shadow positions. This is directly analogous to traditional structure from motion where camera positions and 3D feature positions are estimated only from observed 2D feature positions.
Our evaluation on simulated and real scenes shows that our method yields light estimates that are stable and more accurate than existing techniques while having a considerably simpler setup and requiring less manual labor.
Hiroaki Santo obtained his bachelor's and master's degree in computer science from Osaka University, Japan and is currently pursuing his PhD degree in Yasuyuki Matsushita's computer vision lab at Osaka University. His research interests are mainly in photometric stereo and machine learning.