ZCam

ZCam is a brand of time-of-flight camera products for video applications by Israeli developer 3DV Systems. The ZCam supplements full-color video camera imaging with real-time range imaginginformation, allowing for the capture of video in 3D.

The original ZCam, released in 2000, was an ENG video camera add-on used for digital video compositing. Before agreeing in March 2009 to sell its assets to Microsoft, 3DV had planned to release a ranging video webcam (previously called the Z-Sense), also under the name ZCam. The ZCam webcam was one of several competing real-time range imaging camera products in development that target home game controller applications.

Technology.

The ZCam's time-of-flight camera system features a near-infrared (NIR) pulse illumination component, as well as an image sensor with a fast gating mechanism. Based on the known speed of light, ZCam coordinates the timing of NIR pulse wave emissions from the illuminator with the gating of the image sensor, so that the signal reflected from within a desired depth range is captured exclusively. The amount of pulse signal collected for each pixel corresponds to where within the depth range the pulse was reflected from, and can thus be used to calculate the distance to a corresponding point on the captured subject.

Due to the fast timing required for light-based time-of-flight, the ZCam uses custom hardware for illumination and gating. The illuminator is a series of NIR laser diodes around the lens barrel, switched by special high-speed driver circuits that produce pulses with a rise time and fall time of less than one nanosecond. Previously using an image intensifier for gating the image sensor, 3DV later developed a special solid-state image shutter, in the form of a gallium arsenide-based electro-optical chip that is mounted atop the image sensor. The company was reportedly developing a gating solution based on less-expensive CMOS-process fabrication.

The depth map

The time-of-flight camera is optically matched with a corresponding video camera, allowing the RGB video and range imaging to integrated together. 3DV refers to the combination as "RGBD," in which "D" refers to a "depth" or "distance" channel.

Microsoft uses the ZCam technology for a motion-sensing controller system for the Xbox 360 video game console or its successor. This speculation increased in the month leading up to Microsoft's announcement of the Kinect 3D depth-sensing device at the 2009 Electronic Entertainment Expo, during which leaked information about that device prompted frequent comparisons with the ZCam.