Rapid BRDF Measurement Using an Ellipsoidal Mirror and a Projector

Measuring a bidirectional reflectance distribution function (BRDF) requires long time because a target object must be illuminated from all incident angles and the reflected light must be measured from all reflected angles. In this paper, we introduce a rapid BRDF measuring system using an ellipsoidal mirror and a projector. Since the system changes incident angles without a mechanical drive, dense BRDF can be rapidly measured. Moreover, it is shown that the S/N ratio of the measured BRDF can be significantly increased by multiplexed illumination based on the Hadamard matrix.