BTF Measurements
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.
A table is provided which gives the illumination
and viewing directions associated with each of the 205 images.
The images are stored as 24-bit BMP files, and can readily be
radiometrically calibrated .
The 205 images for each sample can be downloaded
via anonymous ftp
from the directories sample01, sample02, ... sample61
in
curet.cs.columbia.edu/curet/data
. To download an entire
set of images for a particular sample, e.g. sample11, use the following
sequence of commands:
ftp curet.cs.columbia.edu
cd /curet/data
cd sample11
prompt
binary
mget *
Any of the 205 images for each sample can be
downloaded individually by
clicking on the appropriate sample in the
graphical sample-list
or the
text-only sample-list .
An illustration of 3D texture mapping using the
images of the database is provided.
[Return to Database Home Page]