Synchronizing active illumination cameras
First Claim
Patent Images
1. A system for controlling operation of a plurality of active illumination time of flight (TOF) range cameras, the system comprising:
- a hub configured to communicate with mobile communication devices and comprising a database of active illumination TOF range cameras subscribed to the system; and
a set of computer executable instructions comprised in each subscriber TOF range camera that configures the camera to communicate with the hub when located in a same imaging neighbourhood with other subscriber TOF range cameras to establish a frequency division multiplexing (FDM) imaging mode of operation in which each of the subscriber TOF range cameras is assigned a different FDM imaging frequency that the TOF range camera uses to determine a modulation period for light that the camera transmits to illuminate a scene that the camera images and a modulation period for modulating sensitivity of the TOF range camera to register light reflected by features in the scene from the transmitted modulated light.
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Abstract
Apparatus for controlling a plurality of active illumination cameras to operate in a frequency division multiplexed operating mode to acquire images of scenes that the cameras image.
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Citations
20 Claims
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1. A system for controlling operation of a plurality of active illumination time of flight (TOF) range cameras, the system comprising:
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a hub configured to communicate with mobile communication devices and comprising a database of active illumination TOF range cameras subscribed to the system; and a set of computer executable instructions comprised in each subscriber TOF range camera that configures the camera to communicate with the hub when located in a same imaging neighbourhood with other subscriber TOF range cameras to establish a frequency division multiplexing (FDM) imaging mode of operation in which each of the subscriber TOF range cameras is assigned a different FDM imaging frequency that the TOF range camera uses to determine a modulation period for light that the camera transmits to illuminate a scene that the camera images and a modulation period for modulating sensitivity of the TOF range camera to register light reflected by features in the scene from the transmitted modulated light. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of imaging a scene using a plurality of active illumination TOF range cameras, the method comprising:
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establishing a wireless local area network (WLAN) over which the plurality of TOF range cameras communicate; and appointing one of the cameras to transmit messages to other of the TOF range cameras assigning them different FDM imaging frequencies of operation at which to operate to acquire ranges images of scenes, wherein the frequency of operation of each TOF range camera of the plurality of TOF range cameras is established based on receiving an assigned frequency of operation from at least one other TOF range camera in the imaging neighborhood or assigning different frequencies of operation to the other TOF range cameras in the imaging neighborhood.
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18. An active illumination time of flight (TOF) range camera operable to determine distances to features in a scene, the TOF camera comprising:
- a light source configured to transmit temporally modulated light having a modulation period to illuminate the scene;
a photosensor comprising at least one pixel configured to register amounts of light reflected from the transmitted modulated light by a feature in the scene that is imaged on a pixel of the at least one pixel; and
a controller configured to;
establish an FDM imaging frequency of operation for the TOF range camera based on a presence of at least one other active illuminating camera in an imaging neighbourhood of the TOF range camera whose operation may interfere with operation of the TOF range camera, wherein the FDM imaging frequency of operation is established based on receiving an assigned FDM imaging frequency of operation from at least one other active illuminating camera in the imaging neighborhood or assigning different frequencies of operation to the TOF range camera and the at least one other active illuminating camera in the imaging neighborhood;
use the established FDM imaging frequency to determine a modulation period for the temporally modulated light that the TOF range camera transmits, and modulate sensitivity of the at least one pixel to register light reflected by features in the scene from the transmitted modulated light; and
determine a distance to the feature imaged on the pixel of the at least one pixel based on an amount of light that the pixel registers during modulation of the sensitivity of the at least one pixel. - View Dependent Claims (19, 20)
- a light source configured to transmit temporally modulated light having a modulation period to illuminate the scene;
Specification