Rather than using the millions of pixels normally found in 3D imaging cameras, a team of scientists from Glasgow University have cut that down to a single, light-sensing pixel, not only making the camera smaller, but much cheaper as well. Furthermore, along with creating 3D images, the scientists claim that the new single-pixel camera is capable of seeing frequencies beyond the visible spectrum of light.
Being cheaper than a standard digital camera, coupled with being able to see a wider breadth of the visible spectrum, certainly gives this single-pixel camera two important qualities: it’s cheaper and can snap pictures of more things. However, they won’t begin replacing the cameras in our phones or tucked away in our pockets just yet — the Glasgow camera relies on external hardware and signals. The research team’s setup uses four cameras to record one image, and is made possible with the help of a separate lighting system. The four single-pixel detection rigs are set up around an object, then the separate lighting system flashes the object in something of a strobe light manner, creating what the team describes as something similar to the black-and-white pattern of a crossword puzzle. The light from the white spots of the pattern reflects back into the single-pixel detectors, and is recorded. The more frequent the overlap of the white spots of the pattern, the more light is intensely reflected back to the detectors.
Once the detectors have recorded the intensities of the reflected light, they are fed into a computer, which in turn runs an algorithm to produce a 2D image. In order to create the 3D image, the results from the other three cameras are combined — think of it like a collage that creates depth. The technique is known as shape from shade.
A standard multi-megapixel system requires a high degree of calibration and accuracy in order to turn 2D information into a 3D image, but the single-pixel camera system doesn’t require that calibration, and the results are similarly accurate and only take a few seconds to create. The single-pixel method is also capable of detecting images beyond the regular spectrum in which standard digital cameras operate, leading the scientists to believe that the system can be used for medical imaging, or to find oil by detecting gases that leak from deposits deep underground.
The Glasgow team also notes that its single-pixel system only costs a few bucks (or pounds, since they’re from Glasgow), whereas a standard 3D system that produces similar results costs tens of thousands of dollars. Currently, the system used in the lab is not portable, thus making it much less useful, regardless of how far beyond the visible spectrum it can detect. However, the team says that a portable version of the system can be made “quite easily,” though they didn’t reveal exactly how, as that would probably be giving away a prized secret.
Research paper: DOI: 10.1126/science.1234454 – “3D Computational Imaging with Single-Pixel Detectors”