Researchers at Columbia University and Utrecht University have collaborated in an extensive investigation of the visual appearance of real-world surfaces. This joint effort, sponsored in part by REALISE of the European Commission, the National Science Foundation and by DARPA/ONR under the MURI Grant No. N00014-95-1-0601 has resulted in 3 databases:

1. BRDF (bidirectional reflectance distribution function) database with reflectance measurements for over 60 different samples, each observed with over 200 different combinations of viewing and illumination directions.

2. BRDF parameter database with fitting parameters from two recent BRDF models: the Oren-Nayar model and the Koenderink et al. representation. These BRDF parameters can be directly used for both image analysis and image synthesis.

3. BTF (bidirectional texture function) database with image textures from over 60 different samples, each observed with over 200 different combinations of viewing and illumination directions. Each of these databases is made publicly available for research purposes.