| Volume 23 Issue 12 - Publication Date: 1 December 2004 |
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| Stereoscopic Light Stripe Scanning:
Interference Rejection, Error Minimization and Calibration |
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| Geoffrey Taylor and Lindsay
Kleeman Department of Electrical and Computer Systems Engineering,
Monash University, Clayton 3800, Victoria, Australia |
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| This paper addresses the
problem of rejecting interference due to secondary specular reflections,
cross-talk and other mechanisms in an active light stripe scanner for
robotic applications. Conventional scanning methods control the environment
to ensure the brightness of the stripe exceeds that of all other features.
However, this assumption is likely to be violated for a robot operating
in an uncontrolled environment. Robust scanning methods already exist,
but suffer from problems including assumed scene structure, acquisition
delay, lack of error recovery, and incorrect modeling of measurement noise.
We propose a robust technique that overcomes these problems, using two
cameras and knowledge of the light plane orientation to disambiguate the
primary reflection from spurious measurements. Unlike other robust techniques,
our validation and reconstruction algorithms are optimal with respect
to sensor noise. Furthermore, we propose a procedure to calibrate the
system using measurements of an arbitrary non-planar target, providing
robust validation independently of ranging accuracy. Finally, our robust
techniques allow the sensor to operate in ambient indoor light, allowing
color and range to be implicitly registered. An experimental scanner demonstrates
the effectiveness of the proposed techniques. Source code and sample data
are provided in the multimedia extensions. |
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| Multimedia Key |
= Video |
 = Data |
= Code |
= Image |
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|
Extension |
Type |
Description |
1 |
|
Example
One: VRML 97 model of single-camera range map for mirror scene
(1.1 MB) |
2 |
|
Example
Two: VRML 97 model of doublecamera range map for mirror scene
(0.8 MB) |
3 |
|
Example
Three: VRML97 model of robust scanner range map for mirror scene
(1.0 MB) |
4 |
|
Example
Four: VRML97 model of typical domestic objects (1.4 MB) |
5 |
|
Example
Five: VRML97 model of typical domestic objects (1.4 MB) |
6 |
|
Example
Six: C++ source code for light stripe calibration/noise rejection
with sample results (78 kb) |
7 |
|
Example
Seven: Rawstereo image sequence of corner calibration target
scan [zip file] (31.6 MB) |
8 |
|
Example
Eight: Rawstereo image sequence of mirror experiment scan [zip
file] (44.8 MB) |
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