The Kinect device, developed by Microsoft for use with their Xbox gaming console, has been touted as a revolutionary device that can track and respond to human movements in real-time without the need for a game controller. But how does this device work? Some explanations of the device base it on a simple echo of light: “The camera transmits invisible near-infrared light and measures its “time of flight” after it reflects off the objects. Time-of-flight works like sonar: If you know how long the light takes to return, you know how far away an object is.” (wired.com). In this article, we’ll explore the true workings of the Kinect device and how it is able to track human movements so accurately.
The Echo of Light Myth
Contrary to popular belief, the Kinect device does not use a time of flight mechanism to track movements. Instead, the device is a structured light scanner that projects an infrared pattern (invisible to humans) onto the surrounding environment. This infrared pattern is then read by an infrared camera and the 3D information is reconstructed from the distortions of the pattern. This results in the creation of a depth channel which is then made available through USB.
To understand how this works, it’s important to understand the concept of structured light. In short, structured light is a method of scanning a scene or object using a known and structured light pattern. When this pattern is projected onto the scene or object, it gets distorted in a predictable way that is caused by the depth of the object or scene. By analyzing the resulting distortion, it is possible to reconstruct the 3D geometry of the scene or object.
Understanding PrimeSense’s Technology
The underlying technology used in the Kinect device was developed by PrimeSense, an Israeli tech company specializing in motion sensing and recognition technology. According to the company, the Kinect device projects a structured light code made up of thousands of infrared dots onto the surrounding environment. These dots create a unique pattern that is captured by the device’s infrared camera.
Using a sophisticated parallel computational algorithm, PrimeSense is able to decipher the received light coding and use it to generate a highly accurate, real-time 3D model of the scene. The system is capable of filtering out ambient light noise and can achieve a resolution of 1cm at 2 meters.
Seeing the Infrared Pattern
Despite the infrared pattern being invisible to the human eye, it is still possible to see it using a simple trick. First, turn off all the lights in the room and turn on the Kinect device. Then, use your cellphone camera to view the surrounding environment. Generally, these camera sensors are sensitive to IR, which appears as green on the display. You can verify this by trying the same with a TV remote and pressing the buttons. The LED should turn green.
Conclusion
The Kinect device uses structured light scanning technology to track and respond to human movements in real-time. While the notion of a time of flight mechanism echoes off a surface is a popular myth, the true workings of the Kinect device are far more complex and sophisticated. By projecting an infrared pattern onto the surrounding environment and then analyzing the distortions in the pattern, the device is able to create an accurate real-time 3D model of the scene. PrimeSense’s technology is capable of filtering out ambient noise and can achieve a resolution of 1cm at 2 meters.
How does the Kinect device work?
How Does the Kinect Device Work?
The Kinect device, developed by Microsoft for use with their Xbox gaming console, has been touted as a revolutionary device that can track and respond to human movements in real-time without the need for a game controller. But how does this device work? Some explanations of the device base it on a simple echo of light: “The camera transmits invisible near-infrared light and measures its “time of flight” after it reflects off the objects. Time-of-flight works like sonar: If you know how long the light takes to return, you know how far away an object is.” (wired.com). In this article, we’ll explore the true workings of the Kinect device and how it is able to track human movements so accurately.
The Echo of Light Myth
Contrary to popular belief, the Kinect device does not use a time of flight mechanism to track movements. Instead, the device is a structured light scanner that projects an infrared pattern (invisible to humans) onto the surrounding environment. This infrared pattern is then read by an infrared camera and the 3D information is reconstructed from the distortions of the pattern. This results in the creation of a depth channel which is then made available through USB.
To understand how this works, it’s important to understand the concept of structured light. In short, structured light is a method of scanning a scene or object using a known and structured light pattern. When this pattern is projected onto the scene or object, it gets distorted in a predictable way that is caused by the depth of the object or scene. By analyzing the resulting distortion, it is possible to reconstruct the 3D geometry of the scene or object.
Understanding PrimeSense’s Technology
The underlying technology used in the Kinect device was developed by PrimeSense, an Israeli tech company specializing in motion sensing and recognition technology. According to the company, the Kinect device projects a structured light code made up of thousands of infrared dots onto the surrounding environment. These dots create a unique pattern that is captured by the device’s infrared camera.
Using a sophisticated parallel computational algorithm, PrimeSense is able to decipher the received light coding and use it to generate a highly accurate, real-time 3D model of the scene. The system is capable of filtering out ambient light noise and can achieve a resolution of 1cm at 2 meters.
Seeing the Infrared Pattern
Despite the infrared pattern being invisible to the human eye, it is still possible to see it using a simple trick. First, turn off all the lights in the room and turn on the Kinect device. Then, use your cellphone camera to view the surrounding environment. Generally, these camera sensors are sensitive to IR, which appears as green on the display. You can verify this by trying the same with a TV remote and pressing the buttons. The LED should turn green.
Conclusion
The Kinect device uses structured light scanning technology to track and respond to human movements in real-time. While the notion of a time of flight mechanism echoes off a surface is a popular myth, the true workings of the Kinect device are far more complex and sophisticated. By projecting an infrared pattern onto the surrounding environment and then analyzing the distortions in the pattern, the device is able to create an accurate real-time 3D model of the scene. PrimeSense’s technology is capable of filtering out ambient noise and can achieve a resolution of 1cm at 2 meters.