0430591 20240111140849.720140912235959.9 Praha ÚTIA AV ČR 2014 7 s. E Research Report 2342 measurement setup BTF ABRDF visual psychophysics material appearance 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. cav_un_auth*0292156 Krupička Mikuláš Rozpoznávání obrazu Department of Pattern Recognition RO RO UTIA-B Department of Pattern Recognition Ústav teorie informace a automatizace AV ČR, v. v. i. hypertextový soubor PDF http://library.utia.cas.cz/separaty/2014/RO/filip-0430591.pdf 4MB 239294 EC FP7, European Reintegration Grant BE cav_un_auth*0301476 GA14-02652S GA ČR CZ cav_un_auth*0303412 GAP103/11/0335 GA ČR cav_un_auth*0273627 A photo-realistic representation of material appearance can be achieved by means of bidirectional texture function (BTF) capturing a material's appearance for varying illumination, viewing directions, and spatial pixel coordinates. BTF captures many non-local effects in material structure such as inter-reflections, occlusions, shadowing, or scattering. The acquisition of BTF data is usually time and resource-intensive due to the high dimensionality of BTF data. This results in expensive, complex measurement setups and/or excessively long measurement times. We propose an approximate BTF acquisition setup based on a simple, affordable mechanical gantry containing a consumer camera and two LED lights. It captures a very limited subset of material surface images by shooting several video sequences. A psychophysical study comparing captured and reconstructed data with the reference BTFs of seven tested materials revealed that results of our method show a promising visual quality. 2015 BD 4 O 4o 20231122140354.1 RVO:67985556 http://hdl.handle.net/11104/0236063 S 2014 Soubory v repozitáři: 0430591.pdf 2014 Praha ÚTIA AV ČR hypertextový soubor PDF 4MB