Clever math could enable a high-quality 3-D camera so simple, cheap and power-efficient that it could be incorporated into handheld devices.
The MIT researchers’ system [...] uses only a single light detector — a one-pixel camera. But by using some clever mathematical tricks, it can get away with firing the laser a limited number of times.
Indeed, the algorithm lets the researchers get away with relatively crude hardware. Their system measures the time of flight of photons using a cheap photodetector and an ordinary analog-to-digital converter — an off-the-shelf component already found in all cellphones. The sensor takes about 0.7 nanoseconds to register a change to its input.
CoDAC is a new time-of-flight based range measurement system for acquiring depth maps of piecewise-planar scenes with high spatial resolution using a single, omnidirectional, time-resolved photodetector and no scanning components. [...]
Our technique, CoDAC, is based on the TOF distance measurement principle. In contrast to a regular TOF camera, CoDAC uses a pulsed light source to illuminate a spatial light modulator. The spatial light modulator selectively illuminates the scene with a randomly-chosen checkerboard pattern by selectively blocking some of the light. All the light reflected from the scene is focused at a single, time-resolved photodetector. The photodetector produces an electrical signal, which is in turn sampled and stored. This process of illumination, integration and sampling is repeated for a small number of randomly-chosen binary patterns. Finally, the time samples collected through this acquisition are computationally processed using a parametric signal processing framework to reconstruct the scene depth map.
It will be a little time before a commercial system is available - at
the moment the MIT team is working on extending the method to curved
surfaces - but Intel has already invested $100,000 as part of its
innovation Fellowship program.
Having portable depth detectors small enough to fit in a mobile phone really would open up a whole new world of apps.