A new 3D Nano-Camera was unveiled this week by researchers from the Massachusetts Institute of Technology (MIT) Media Lab. It is a 3D camera that can capture translucent objects and it operates at the speed of light, so you can observe and record light as it moves past and through objects. This could potentially be used in medical imaging and collision-avoidance detectors for cars. It also aims to improve accuracy of motion tracking and gesture-recognition devices used in interactive gaming.
The group of MIT students created this new Nano-Camera by using the same ‘Time of Flight’ technology as used in Microsoft’s second gen Kinect sensor which comes with the Xbox One. With the technology, the image depth is captured by calculating how long it takes to reflect the light signal off a surface and return to the sensor of the camera to strike a pixel.
Conventional ‘Time of Flight’ cameras such as the one used by the Kinect find it hard to capture translucent objects in 3D, “That is because the light that bounces off the transparent object and the background smear into one pixel on the camera. Using our technique you can generate 3D models of translucent or near-transparent objects”, explains MIT graduate student Achuta Kadambi, one of those who worked on the project. It can also accurately measure light signals even in adverse weather such as fog or rain.
How did they do it?
The team used an encoding technique that’s used widely in the telecommunications industry to calculate the distance a signal has travelled. “We use a new method that allows us to encode information in time,” says Ramesh Raskar, another student who worked on the project, “when the data comes back, we can do calculations that are very common in the telecommunications world, to estimate different distances from the single signal.” It is a similar idea to the already existing techniques that clear up blurring in photographs.
This discovery brings great cost advantages to the field of 3D Nano-Cameras as the team created their imaging device by using inexpensive LEDs that move back and forth at nanosecond periods (on thousand-millionth of a second). It delivers similar results to the Femto-Camera’s femtography, a trillion-frame-per-second camera created by Raskar’s group back in 2011 that captures light as it passes through a scene. With only a very slightly reduction in quality, the Nano-Camera surely seems much more accessible to users at just a pinch (0.1 per cent) of the $500,000 cost of making the Femto-Camera.