Orthogonal Illuminations in Two Light-Source Photometric Stereo

Ryszard Kozera (1) , Alexander Prokopenya (1)

1 SGGW - Warsaw University of Life Sciences

In this paper we investigate the case of ambiguous shape reconstruction from two light-source photometric stereo based on illuminating the unknown Lambertian surface. So-far this problem is merely well-understood for two linearly independent light-source directions with one illumination assumed as overhead. As already established, a necessary and sufficient condition to disambiguate the entire shape reconstruction process is controlled by the satisfaction of the corresponding second-order linear PDE with constant coefficients in two independent variables. This work extends the latter to an arbitrary pair of light-source directions transforming the above constraint into a special nonlinear PDE. In addition, a similar ambiguity analysis is also performed for a special configuration of two light-source directions assumed this time as orthogonal and contained in the vertical plane. Finally, this work is supplemented by illustrative examples exploiting symbolic computation used within a framework of continuous reflectance map model (i.e. an image irradiance equation) and applied to a genuine Lambertian surfaces.

Mots clés: Photometric stereo; Image irradiance equation; Ambiguity in shape reconstruction; Computer vision

Domaines: Informatique [cs]; Sciences de l'information et de la communication

Ryszard Kozera, Alexander Prokopenya. Orthogonal Illuminations in Two Light-Source Photometric Stereo. 15th IFIP International Conference on Computer Information Systems and Industrial Management (CISIM), Sep 2016, Vilnius, Lithuania. pp.402-415, ⟨10.1007/978-3-319-45378-1_36⟩. ⟨hal-01637521⟩