Jornal article

Filip J., Haindl M.

Lecture Notes in Computer Science

2006

4153

475-484

0302-9743

Ing. Jiří Filip, Ph.D. (ÚTIA - Oddělení rozpoznávání obrazů)

BTF, texture, synthesis, MRF, clustering, BRDF

The highest fidelity representations of realistic real-world materials currently used comprise Bidirectional Texture Functions (BTF). The BTF is a six imensional function depending on view and illumination directions as well as on planar texture coordinates. The huge size of such measurements, typically in the form of thousands of images covering all possible combinations of illumination and viewing angles, has prohibited their practical exploitation and obviously some compression and modelling method of these enormous BTF data spaces is inevitable. The proposed approach combines BTF spatial clustering with cluster index modelling by means of an efficient Markov random field model. This method allows to generate seamless cluster index of arbitrary size to cover large virtual 3D objects surfaces. The method represents original BTF data using a set of local spatially independent Bidirectional Reflectance Distribution Function (BRDF) values which are combined according to synthesised cluster index and illumination /
viewing directions. BTF data compression using this method is about $1:100$ and their synthesis is very fast.