We use a Fourier optics multispectral instrument to measure the BRDF of isotropic and anisotropic samples. The capacity to measure rapidly high angular BRDF patterns is useful to study complex BRDF behaviors in particular for anisotropic surfaces. Metallic two dimensional structured surfaces exhibit different diffusion properties along particular directions. Brushed metallic samples coated with transparent protective layer show complex BRDF patterns modulated by interference fringes due to the coating. The color of the surface is driven by the anisotropic diffusion and the coating thickness. The surface of OLED displays shows also complex scattering patterns due to the periodic pixel structure. We examine how to use spectral BRDF measurements to simulate the aspect of the surfaces and how to take into account the anisotropy in practice. Results are compared in some cases to aspect measurements made with multispectral imaging and punctual illumination source. Optical properties of curved OLED TV under parasitic illuminations are also presented.
Pierre Boher, Thierry Leroux, Thibault Bignon, Véronique Collomb-Patton, "Multispectral BRDF measurements on anisotropic samples: application to metallic surfaces and OLED displays" in Proc. IS&T Int’l. Symp. on Electronic Imaging: Measuring, Modeling, and Reproducing Material Appearance, 2016, https://doi.org/10.2352/ISSN.2470-1173.2016.9.MMRMA-359