Students Create Camera Operating at Speed of Light for Just $500
9 December 2013
Students at the MIT Media Lab have created an innovative "nano-camera," costing just $500, which can be used in medical imaging and collision-avoidance detectors for vehicles and for enhancing the precision of motion tracking and gesture-recognition devices applied in interactive gaming.
The three-dimensional camera, which can perform at the speed of light, was presented in late November at Siggraph Asia in Hong Kong. It can produce 3-D models of translucent or near-transparent objects thanks to an encoding technique generally applied in the telecommunications industry to estimate the distance a signal has travelled, said Ramesh Raskar, an associate professor of media arts and sciences and leader of the Camera Culture group within the Media Lab.
Raskar was part of the team that developed the camera, together with graduate MIT students Achuta Kadambi, Refael Whyte and Ayush Bhandari, and Christopher Barsi and Lee Streeter from the University of Waikato in New Zealand.
The method enables encoding information in time, making it possible to estimate different distances from a single signal, Raskar said.
The creation of the nano-camera follows Raskar's success in developing a trillion-frame-per-second camera that can capture a single pulse of light as it travels through a scene. This is achieved by probing the scene with a femtosecond impulse of light and taking an image each time with the help of fast but costly laboratory-grade optical equipment. The cost of creating this "femto-camera" is $500,000.
What distinguishes the "nano-camera" from its expensive predecessor is the continuous signal oscillating at nanosecond periods that it uses to probe the scene, allowing the researchers to use cheap hardware like light-emitting diodes (LEDs). Such off-the-shelf equipment makes it possible for the camera to reach a time resolution within one order of magnitude of femtophotography for just $500. This means that, by changing the code, the researchers managed to unmix the light paths and visualize light moving across the scene, scoring similar results to the "femto-camera" at an extremely low price, Kadambi said.