As the physical and digital worlds converge, there is an increasing need for creating
digital models of people and objects. A digital model typically consists of geometric
information, indicating the shape of the object's surfaces, and reflectance information,
indicating how each part of the object reflects light. Acquiring the geometry of an object
can be done in many ways, from laser scanning, to structured light, to passive photogrammetry,
the latter of which can be performed from photos all shot at the same instant. Acquiring the
reflectance of an object - the coloration of each surface, which parts are diffuse, which
parts are shiny, and high-resolution surface detail - typically involves photographing the
object under a series of lighting conditions and fitting the observations to a reflectance
model. With the reflectance captured, the digital model can be digitally rendered as if lit
by the light of any desired environment, making the object a useful digital asset.
Single-shot scanning techniques, where the acquisition takes place at a single brief moment
of time, make model acquisition more efficient and much easier to apply to dynamic subjects
such as facial performances. However, since the subject is lit by just one lighting condition,
not much about the object's reflectance can be captured beyond its appearance under diffuse
illumination. Far more useful would be to have, at each surface point, a measurement of the
subject's diffuse color, its specular component, and a highresolution
measurement of its surface normal.
In this paper, we present a novel single-shot scanning technique which uses a color polarized
illumination setup to record precisely these measurements. The subject is placed in a sphere
of red, green, and blue LEDS, with horizontallyoriented and vertically-oriented linear
polarizers distributed throughout. With this setup, different gradient directions of light
are produced on the different polarizations of the color channels, and the subject is
photographed with a set of cameras some of which are polarized horizontally and some of
which are polarized vertically. We leverage the fact that for dielectric materials including
skin, the specular reflection component preserves the polarization, and the diffuse component
depolarizes the light. These lighting conditions and cameras allow the diffuse color, specular
intensity, and photometric surface orientation to be estimated at each pixel location on the
object, yielding a single-shot scanning technique for both geometry and reflectance. We
demonstrate the technique with two experimental setups: one using two DSLR cameras and a
polarizing beam splitter to record reflectance from a single viewpoint, and a multi-view
setup with a set of DSLR cameras placed around the subject with
differently oriented polarization filters.