Circularly Polarized Spherical Illumination Reflectometry
ACM SIGGRAPH Asia 2010
Abhijeet Ghosh    Tongbo Chen    Pieter Peers    Cyrus A. Wilson    Paul Debevec   
USC Institute for Creative Technologies



Renderings under environmental illumination of subjects with spatially varying reflectance acquired using circularly polarized spherical illumination.

Abstract

We present a novel method for surface reflectometry from a few observations of a scene under a single uniform spherical field of circularly polarized illumination. The method is based on a novel analysis of the Stokes reflectance field of circularly polarized spherical illumination and yields per-pixel estimates of diffuse albedo, specular albedo, index of refraction, and specular roughness of isotropic BRDFs. To infer these reflectance parameters, we measure the Stokes parameters of the reflected light at each pixel by taking four photographs of the scene, consisting of three photographs with differently oriented linear polarizers in front of the camera, and one additional photograph with a circular polarizer. The method only assumes knowledge of surface orientation, for which we make a few additional photometric measurements. We verify our method with three different lighting setups, ranging from specialized to off-theshelf hardware, which project either discrete or continuous fields of spherical illumination. Our technique offers several benefits: it estimates a more detailed model of per-pixel surface reflectance parameters than previous work, it requires a relatively small number of measurements, it is applicable to a wide range of material types, and it is completely viewpoint independent.

Downloads

SIGGRAPH Asia 2010 Paper
CPSIR_SIGGRAPH_Asia2010.pdf, (29.1MB)

SIGGRAPH Asia 2010 Video
PolSphericalIllumination_SIGAsia2010_H264.mp4, (26.1MB)

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Light Stage 1
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