Monday, October 16, 2006

"OPTICAL: 'Backwards' approach leads to 1-pixel camera"

Remember how digital converters for audio started out at 8 bits, then went to 16 and 24 bits before resetting to 1 bit with oversampling? Engineers at Rice University will propose this week that we reset our megapixel cameras to 1 pixel and our video cameras to 1 voxel, both with oversampling. The 1-pixel camera takes tens of thousands of rapid-fire shots to capture the equivalent of 1 million pixels in an image. So instead of expensive megapixel sensors with separate detectors for red, green and blue, the Rice EEs' approach needs only a 1-pixel multispectral sensor, simplifying hardware resources while enabling images to be formed from spectra never before imaged. The enabling chip for the 1-pixel camera is not the detector used to sense an application-specific spectrum--that could use any technology. Instead, Texas Instruments Inc.'s digital micromirror array is used to project light from the lens onto the sensor. The micromirror array is the same chip that's used in Digital Light Processor televisions. Here, the lens focuses light onto the 1,024 x 768-pixel digital micromirror chip, which in turn projects all of its light into a single photodiode.