How do you think the new GigE standards will influence the machine vision industry?
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By Keith Reid
"We have the cell phone industry driving the sensors," said Ilias Levis, product manager, Sony Visual Imaging Products (Park Ridge, N.J.). "What used to be a production of thousands of units for CCDs and CMOS now has become millions of units, and that also drives prices and performance and specifications. Today, it's a challenge for industrial and OEM applications to get the attention they once received, because you get so much more volume from the consumer applications. I suppose that's good and bad. It's good because there is a lot of push technology wise, and advancement, but on the other hand the advancement tends to be towards the consumer needs. For example, you get smaller pixels and sensors, but they are sensitive enough? There is still a need for high sensitivity, bigger pixel sized sensors for industrial and OEM applications."
Conversely, the consumer markets are increasingly demanding higher performance. In some cases this is driven by demanding form factors and operating environments. "In mainstream mobile phone applications what you're looking for is the quarter-inch optical form factor, which requires a pretty small pixel array but they want it to be as high resolution as you can get, so this drives tremendous efforts in shrinking the pixel," said Barna. "If you want more pixels you have to make them smaller. There is a tremendous amount of R&D money being spent on shrinking the pixel without giving up performance, and that's a very difficult problem because fewer photons are hitting it, but you still have to try to recover the image accurately as you can. A lot of people haven't necessarily noticed it, but the consumer digital cameras of a few years ago could take pictures in most lighting conditions, and today's cutting-edge digital cameras are throwing that flash almost every time you are inside because the light per pixel is going down."
Marketing also plays a role. Selling consumer technology often centers on performance numbers, and if 1 megapixel is good, than 2 or 3 megapixels must be better—at least in theory. While high megapixel sensors can be required for a range of consumer applications, particularly in prosumer still cameras, more mundane tasks hardly benefit. "People are obsessed with pixels when they look at features for their cameras," said Levis. "For most consumer applications, if you just want to take a picture than anything more than one megapixel in my mind is pretty O.K."
The limitation of optics, illumination and sensitivity come into play with consumer devices used in consumer environments. However, advances in pixel technology promise to help digitally overcome some of the physical limitations found with the camera phone form factor. If the resolution can increase sufficiently, then it will allow for an effective optical zoom to be applied to the mobile market.
One sensor-specific area directly influenced by the consumer market is the increasing use of CMOS sensors. Traditionally, CMOS has been the cheap, lower performing consumer solution while CCD sensors met the high-end requirements. CMOS forms the foundation of most point-and-shoot digital still and video camera systems and Web cams. However, CMOS has greatly increased in performance while CCD has dropped in price, blurring the lines. Kodak is focusing significant efforts on CMOS technology for the range of markets.