Imaging chip breakthrough: 50 times less power, 100 times better dynamic range, 1% of the computing power to compress the images, more energy efficient.
The next advance in cameras is becoming a reality at the University of Rochester. First tests on the chip show that at video rates of 30 frames per second it uses just 0.88 nanowatts per pixel–50 times less than the industry’s previous best. It also trounces conventional chips in dynamic range, which is the difference between the dimmest and brightest light it can record. Existing CMOS sensors can record light 1,000 times brighter than their dimmest detectable light, a dynamic range of 1:1,000, while the Rochester technology already demonstrates a dynamic range of 1:100,000.Imaging chips revolutionized the photography industry, and now the chips themselves are being revolutionized. A pair of newly patented technologies may soon enable power-hungry imaging chips to use just a fraction of the energy used today and capture better images to boot–all while enabling cameras to shrink to the size of a shirt button and run for years on a single battery. Placed in a home, they could wirelessly provide images to a security company when an alarm is tripped, or even allow mapping software like Google’s to zoom in to real-time images at street level. The enormous reduction in power consumption and increase in computing power can also bring cell-phone video calls closer to fruition. The second advance has taken many researchers by surprise. Called “Focal Plane Image Compression,” Bocko and Ignjatovic have figured out a way to arrange photodiodes on an imaging chip so that compressing the resulting image demands as little as 1 percent of the computing power usually needed.
Normally, the light-detecting diodes on a chip are arranged in a regular grid–say 1,000 pixels by 1,000 pixels. A picture is snapped and each diode records the light hitting it. A computer in the camera then runs complex computations to compress the image so that instead of taking up 10 hefty megabytes, it might only take up 100 kilobytes. The common picture type “JPEG,” used on the Web and on many cameras and phones, is an example of this. This compression, unfortunately, takes a tremendous amount of computing power, and hence battery power.