Gesture-Based Interaction with Time-of-Flight Cameras
Gesture-Based Interaction with Time-of-Flight Cameras
Gesture-Based Interaction with Time-of-Flight Cameras
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CHAPTER 2. TIME-OF-FLIGHT CAMERAS<br />
2.7.6 Multi-Camera Setups<br />
The use <strong>of</strong> TOF cameras operating at the same modulation frequency in a configu-<br />
ration where light from one camera’s illumination unit can reach the sensor <strong>of</strong> the<br />
other camera corrupts the range measurement. This is due to the fact that the sensor<br />
cannot disambiguate between the phase shift induced by its own illumination unit<br />
and that <strong>of</strong> another camera.<br />
A straight forward way <strong>of</strong> circumventing this problem is to run the cameras at<br />
different demodulation frequencies. The demodulation approach to measuring the<br />
phase shift responds only to a very narrow band <strong>of</strong> frequencies near the modulation<br />
frequency; all other frequencies will merely appear as an increase in background il-<br />
lumination (Lange, 2000).<br />
A second solution to using several cameras in the same environment is to mod-<br />
ulate the illumination by a pseudo-noise signal. In case each camera uses a different<br />
code, the sensor will only detect the phase shift corresponding to its own emitted<br />
signal (Heinol, 2001).<br />
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