ZCam
Encyclopedia
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 imaging
information, 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.
(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 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
.
, using gesture recognition
to interpret hand and body gestures for controlling the interface, but without many of the complications of a purely 2D-based computer vision
approach. Developing the device since 2005, 3DV completed the initial prototype in late 2006, and officially announced the product in late 2007.
The ZCam webcam had a 60-degree
field of view
, a frame rate
of 60 Hz
, a 1.3 megapixel full color video resolution, and an 8-bit
Quarter VGA ranging resolution (320x240 pixels with 256 depth levels per pixel). Precision was fine as 1-2 centimeters, with a practical ranging limit of 0.5–2.5 meters distance. The webcam connected via a USB
2.0 interface. Demonstrations included a boxing game, an airplane demo, Windows Media Center
hand-gesture control, and a body-gesture Second Life
interface.
3DV stated that the webcam would be priced comparably to other peripherals in the gaming market such as the PlayStation Eye
: less than US$
100, with a bundled
US$69.99 price mentioned as a possibility. The webcam was to include software development kit
s for camera control and gesture recognition. 3DV originally projected the ZCam to be released before the end of 2008, then later revised the projection to 2009. In March 2009, the company agreed to sell its assets including the ZCam to a third party, later confirmed to be Microsoft
. Following these reports, it was speculated that Microsoft would use 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.
Time-of-flight camera
A time-of-flight camera is a range imaging camera system that resolves distance based on the known speed of light, measuring the time-of-flight of a light signal between the camera and the subject...
products for video
Video
Video is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion.- History :...
applications by Israeli developer 3DV Systems. The ZCam supplements full-color video camera
Video camera
A video camera is a camera used for electronic motion picture acquisition, initially developed by the television industry but now common in other applications as well. The earliest video cameras were those of John Logie Baird, based on the electromechanical Nipkow disk and used by the BBC in...
imaging with real-time range imaging
Range imaging
Range imaging is the name for a collection of techniques which are used to produce a 2D image showing the distance to points in a scene from a specific point, normally associated with some type of sensor device....
information, allowing for the capture of video in 3D
Three-dimensional space
Three-dimensional space is a geometric 3-parameters model of the physical universe in which we live. These three dimensions are commonly called length, width, and depth , although any three directions can be chosen, provided that they do not lie in the same plane.In physics and mathematics, a...
.
The original ZCam, released in 2000, was an ENG video camera add-on used for digital video compositing
Compositing
Compositing is the combining of visual elements from separate sources into single images, often to create the illusion that all those elements are parts of the same scene. Live-action shooting for compositing is variously called "chroma key", "blue screen", "green screen" and other names. Today,...
. Before agreeing in March 2009 to sell its assets to Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
, 3DV had planned to release a ranging
Ranging
Ranging is a process or method to determine the distance from one location or position to another location or position. Another term for this method is lateration, see unilateration...
video webcam
Webcam
A webcam is a video camera that feeds its images in real time to a computer or computer network, often via USB, ethernet, or Wi-Fi.Their most popular use is the establishment of video links, permitting computers to act as videophones or videoconference stations. This common use as a video camera...
(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
Game controller
A game controller is a device used with games or entertainment systems used to control a playable character or object, or otherwise provide input in a computer game. A controller is typically connected to a game console or computer by means of a wire, cord or nowadays, by means of wireless connection...
applications.
Technology
The ZCam's time-of-flight camera system features a near-infraredInfrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
(NIR) pulse illumination component, as well as an image sensor
Image sensor
An image sensor is a device that converts an optical image into an electronic signal. It is used mostly in digital cameras and other imaging devices...
with a fast gating
Gating
-Neurobiology:*Gating , the opening or closing of ion channels*Sensory gating, an automatic process by which the brain adjusts to stimuli*Synaptic gating, neural circuits suppressing inputs through synapses...
mechanism. Based on the known speed of light
Speed of light
The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...
, ZCam coordinates the timing of NIR pulse wave
Pulse wave
A pulse wave or pulse train is a kind of non-sinusoidal waveform that is similar to a square wave, but does not have the symmetrical shape associated with a perfect square wave. It is a term common to synthesizer programming, and is a typical waveform available on many synths. The exact shape of...
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
Photographic lens
A camera lens is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.While in principle a simple convex lens will suffice, in...
barrel, switched by special high-speed driver circuits that produce pulses with a rise time
Rise time
In electronics, when describing a voltage or current step function, rise time refers to the time required for a signal to change from a specified low value to a specified high value...
and fall time
Fall time
In electronics, fall time \scriptstyle t_f\, is the time required for the amplitude of a pulse to decrease from a specified value to another specified value...
of less than one nanosecond
Nanosecond
A nanosecond is one billionth of a second . One nanosecond is to one second as one second is to 31.7 years.The word nanosecond is formed by the prefix nano and the unit second. Its symbol is ns....
. Previously using an image intensifier
Image intensifier
An image intensifier tube is a vacuum tube device for increasing the intensity of available light in an optical system to allow use under low light conditions such as at night, to facilitate visual imaging of low-light processes such as fluorescence of materials to X-rays or gamma rays, or for...
for gating the image sensor, 3DV later developed a special solid-state
Solid state (electronics)
Solid-state electronics are those circuits or devices built entirely from solid materials and in which the electrons, or other charge carriers, are confined entirely within the solid material...
image shutter
Shutter (photography)
In photography, a shutter is a device that allows light to pass for a determined period of time, for the purpose of exposing photographic film or a light-sensitive electronic sensor to light to capture a permanent image of a scene...
, in the form of a gallium arsenide
Gallium(III) arsenide
Gallium arsenide is a compound of the elements gallium and arsenic. It is a III/V semiconductor, and is used in the manufacture of devices such as microwave frequency integrated circuits, monolithic microwave integrated circuits, infrared light-emitting diodes, laser diodes, solar cells and...
-based electro-optical
Electro-optics
Electro-optics is a branch of technology involving components, devices and systems which operate by modification of the optical properties of a material by an electric field...
chip
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
that is mounted atop the image sensor. The company was reportedly developing a gating solution based on less-expensive CMOS
CMOS
Complementary metal–oxide–semiconductor is a technology for constructing integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits...
-process fabrication.
The time-of-flight camera is optically matched with a corresponding video camera, allowing the RGB
RGB color space
An RGB color space is any additive color space based on the RGB color model. A particular RGB color space is defined by the three chromaticities of the red, green, and blue additive primaries, and can produce any chromaticity that is the triangle defined by those primary colors...
video and range imaging to integrated together. 3DV refers to the combination as "RGBD," in which "D" refers to a "depth" or "distance" channel
Channel (digital image)
Color digital images are made of pixels, and pixels are made of combinations of primary colors. A channel in this context is the grayscale image of the same size as a color image, made of just one of these primary colors. For instance, an image from a standard digital camera will have a red, green...
.
Webcam
Targeted primarily at the video game market, the ZCam webcam was designed to be used as a game controller like the EyeToyEyeToy
The EyeToy is a color digital camera device, similar to a webcam, for the PlayStation 2. The technology uses computer vision and Gesture recognition to process images taken by the camera...
, using gesture recognition
Gesture recognition
Gesture recognition is a topic in computer science and language technology with the goal of interpreting human gestures via mathematical algorithms. Gestures can originate from any bodily motion or state but commonly originate from the face or hand. Current focuses in the field include emotion...
to interpret hand and body gestures for controlling the interface, but without many of the complications of a purely 2D-based computer vision
Computer vision
Computer vision is a field that includes methods for acquiring, processing, analysing, and understanding images and, in general, high-dimensional data from the real world in order to produce numerical or symbolic information, e.g., in the forms of decisions...
approach. Developing the device since 2005, 3DV completed the initial prototype in late 2006, and officially announced the product in late 2007.
The ZCam webcam had a 60-degree
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
field of view
Field of view
The field of view is the extent of the observable world that is seen at any given moment....
, a frame rate
Frame rate
Frame rate is the frequency at which an imaging device produces unique consecutive images called frames. The term applies equally well to computer graphics, video cameras, film cameras, and motion capture systems...
of 60 Hz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
, a 1.3 megapixel full color video resolution, and an 8-bit
8-bit
The first widely adopted 8-bit microprocessor was the Intel 8080, being used in many hobbyist computers of the late 1970s and early 1980s, often running the CP/M operating system. The Zilog Z80 and the Motorola 6800 were also used in similar computers...
Quarter VGA ranging resolution (320x240 pixels with 256 depth levels per pixel). Precision was fine as 1-2 centimeters, with a practical ranging limit of 0.5–2.5 meters distance. The webcam connected via a USB
Universal Serial Bus
USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....
2.0 interface. Demonstrations included a boxing game, an airplane demo, Windows Media Center
Windows Media Center
Windows Media Center is a digital video recorder and media player developed by Microsoft. It is an application that allows users to view and record live television, as well as organize and play music and videos...
hand-gesture control, and a body-gesture Second Life
Second Life
Second Life is an online virtual world developed by Linden Lab. It was launched on June 23, 2003. A number of free client programs, or Viewers, enable Second Life users, called Residents, to interact with each other through avatars...
interface.
3DV stated that the webcam would be priced comparably to other peripherals in the gaming market such as the PlayStation Eye
PlayStation Eye
The PlayStation Eye is a digital camera device, similar to a webcam, for the PlayStation 3. The technology uses computer vision and gesture recognition to process images taken by the camera. This allows players to interact with games using motion and color detection as well as sound through its...
: less than US$
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....
100, with a bundled
Product bundling
Product bundling is a marketing strategy that involves offering several products for sale as one combined product. This strategy is very common in the software business , in the cable television industry Product bundling is a marketing strategy that involves offering several products for sale as...
US$69.99 price mentioned as a possibility. The webcam was to include software development kit
Software development kit
A software development kit is typically a set of software development tools that allows for the creation of applications for a certain software package, software framework, hardware platform, computer system, video game console, operating system, or similar platform.It may be something as simple...
s for camera control and gesture recognition. 3DV originally projected the ZCam to be released before the end of 2008, then later revised the projection to 2009. In March 2009, the company agreed to sell its assets including the ZCam to a third party, later confirmed to be Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
. Following these reports, it was speculated that Microsoft would use the ZCam technology for a motion-sensing controller system for the Xbox 360
Xbox 360
The Xbox 360 is the second video game console produced by Microsoft and the successor to the Xbox. The Xbox 360 competes with Sony's PlayStation 3 and Nintendo's Wii as part of the seventh generation of video game consoles...
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
Electronic Entertainment Expo 2009
The Electronic Entertainment Expo 2009, commonly known as the E3 2009, was the 15th Electronic Entertainment Expo held. The event took place on June 2, 3, and 4 at the Los Angeles Convention Center. E3 is an annual trade show for the computer and video games industry presented by the Entertainment...
, during which leaked information about that device prompted frequent comparisons with the ZCam.