An apparatus for measuring a spatially under-sampled Bidirectional Reflectance Distribution Function (BRDF) of a surface. The apparatus may comprise a first light source directed to illuminate the surface from a first illumination direction, and a plurality of sensors positioned to receive light reflected...http://www.google.es/patents/US7944561?utm_source=gb-gplus-sharePatente US7944561 - Measuring an appearance property of a surface using a bidirectional reflectance distribution function
Measuring an appearance property of a surface using a bidirectional ...
