Image-based brdf measurement.

Technical report PCG-99-1, Program of Computer Graphics, Cornell University, Jan 1999.

We present a new image-based process for measuring surface reflectance rapidly, completely, and accurately. Requiring only a digital camera, a light source, and a convex curved test sample, our method can measure the BRDF with high resolution and accuracy over a very large domain of illumination and reflection directions. We have verified our measurements both by tests of internal consistency and by comparison against measurements made using a gonioreflectometer. We present a new image-based process for measuring the bidirectional reflectance of homogeneous surfaces rapidly, completely, and accurately. For simple sample shapes (spheres and cylinders) the method requires only a digital camera and a stable light source. Adding a 3D scanner allows a wide class of curved near-convex objects to be measured. With measurements for a variety of materials from paints to human skin, we demonstrate the new method's ability to achieve high resolution and accuracy over a large domain of illumination and reflection directions. We verify our measurements by tests of internal consistency and by comparison against measurements made using a gonioreflectometer.