Retrographic sensing for the measurement of surface texture and shape
Computer Vision and Pattern Recognition, 2009
Abstract
We describe a novel device that can be used as a 2.5D
“scanner” for acquiring surface texture and shape. The device consists
of a slab of clear elastomer covered with a reflective skin. When an
object presses on the skin, the skin distorts to take on the shape of
the object’s surface. When viewed from behind (through the elastomer
slab), the skin appears as a relief replica of the surface. A camera
records an image of this relief, using illumination from red, green, and
blue light sources at three different positions. A photometric stereo
algorithm that is tailored to the device is then used to reconstruct the
surface. There is no problem dealing with transparent or specular
materials because the skin supplies its own BRDF. Complete information
is recorded in a single frame; therefore we can record video of the
changing deformation of the skin, and then generate an animation of the
changing surface. Our sensor has no moving parts (other than the
elastomer slab), uses inexpensive materials, and can be made into a
portable device that can be used “in the field” to record surface shape
and texture.
This technology is patent pending.
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More information
The retrographic sensor won a “Best Demo” award at CVPR 2009. An newer version
of the system, called GelSight, was presented at SIGGRAPH 2009 Emerging
Technologies. Please see the GelSight page for videos, FAQ and
instructions for making the sensor.
Cite
BibTeXThis material is based upon work supported by the National Science Foundation under Grant No. 0739255. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.