Authors
Kristin J. Dana, Shree K. Nayar, Bram Van Ginneken, Jan J. Koenderink
Columbia University; Utrecht University
Portals
Summary
We introduce the term BTF (bidirectional texture function) to represent the appearance of texture as a function of viewing and illumination direction. When a surface is macroscopically rough, appearance has a complex dependence on illumination and viewing direction. We measured the BTF of 61 real-world surfaces by recording images of each surface with 205 different combinations of viewing and illumination directions.
Abstract
In this work, we investigate the visual appearance of real-world surfaces and the dependence of appearance on the geometry of imaging conditions. We discuss a new texture representation called the BTF (bidirectional texture function) which captures the variation in texture with illumination and viewing direction. We present a BTF database with image textures from over 60 different samples, each observed with over 200 different combinations of viewing and illumination directions. We describe the methods involved in collecting the database as well as the importqance and uniqueness of this database for computer graphics. A related quantity to the BTF is the familiar BRDF (bidirectional reflectance distribution function). The measurement methods involved in the BTF database are conducive to simultaneous measurement of the BRDF. Accordingly, we also present a BRDF database with reflectance measurements for over 60 different samples, each observed with over 200 different combinations of viewing and illumination directions. Both of these unique databases are publicly available and have important implications for computer graphics.
Contribution
- We discuss a new texture representation called the BTF (bidirectional texture function) which captures the variation in texture with illumination and viewing direction
- We present a BTF database with image textures from over 60 different samples, each observed with over 200 different combinations of viewing and illumination directions
- We also present a BRDF database with reflectance measurements for over 60 different samples, each observed with over 200 different combinations of viewing and illumination directions