Single Pixel Digital Camera, Coming Soon?
Researchers at Rice University in Houston Texas have developed a prototype camera that uses a single pixel image sensor. Actually that’s a bit of an over-simplification, and you needn’t worry too much about the technology coming to a digital camera near you anytime soon. The prototype takes up several square feet of a large laboratory workbench and each picture currently takes around 5 minutes to expose…
The process is called Compressive Sensing light and from an image is scattered using a digital micromirror device (DMD) and picked up using a single photodiode sensor. DMDs are used in video projectors, they’re tiny microchips covered in microscopic mirrors that can be tilted back and forth. In the prototype camera the mirrors are randomly oriented and a ‘snapshot’ of the scattered light is picked up by a photodiode. The process is then repeated several thousand times and the data from the photodiode is assembled, using a complex algorithm into an image.
In addition to future applications in digital still and video cameras it has enormous potential in scientific imaging. Cameras that are sensitive to a range of wavelengths can be built quickly and more cheaply as they only need a single sensor, rather than a costly and complex specialist multi-megapixel image sensor chip.
