0443579 20240111140901.820150526235959.9 000354102200021 84928491965 10.1117/12.2078361 10 s. E cav_un_epca*0444227978-1-62841-488-20277-786XBellinghamSPIE-IS&T2015 BRDF anisotropy detection setup ellipsoidal mirror cav_un_auth*0101086 Filip Jiří Rozpoznávání obrazu Department of Pattern Recognition RO RO UTIA-B Department of Pattern Recognition Ústav teorie informace a automatizace AV ČR, v. v. i. cav_un_auth*0282273 Vávra Radomír Rozpoznávání obrazu Department of Pattern Recognition RO RO UTIA-B Department of Pattern Recognition Ústav teorie informace a automatizace AV ČR, v. v. i. http://library.utia.cas.cz/separaty/2015/RO/filip-0443579.pdf 6MB GA14-02652S GA ČR CZ cav_un_auth*0303412 Many real-world materials exhibit significant changes in appearance when rotated along a surface normal. The presence of this behavior is often referred to as visual anisotropy. Anisotropic appearance of spatially homogeneous materials is commonly characterized by a four-dimensional BRDF. Unfortunately, due to simplicity most past research has been devoted to three dimensional isotropic BRDFs. In this paper, we introduce an innovative, fast, and inexpensive image-based approach to detect the extent of anisotropy, its main axes and width of corresponding anisotropic highlights. The method does not rely on any moving parts and uses only an off-the-shelf ellipsoidal reflector with a compact camera. We analyze our findings with a material microgeometry scan, and present how results correspond to the microstructure of individual threads in a particular fabric. We show that knowledge of a material's anisotropic behavior can be effectively used in order to design a material-dependent sampling pattern so as the material's BRDF could be measured much more precisely in the same amount of time using a common gonioreflectometer. cav_un_auth*0316990 Electronic Imaging 2015 San Francisco 08.02.2015-12.02.2015 US 2016 BD PR RVO:67985556 http://hdl.handle.net/11104/0246780 1 S 0.223 Q4 2015 84928491965 SCOPUS 000354102200021 WOS 6MB cav_un_epca*0444227 Measuring, Modeling, and Reproducing Material Appearance 2015 978-1-62841-488-2 0277-786X 93980P-0-93980P-10 Bellingham SPIE-IS&T 2015 Proceedings of SPIE 9398