Never Miss Another Shot
A new chip set gives digital cameras the rapid-fire shooting ability of 35 mm cameras
Ever try to take pictures one right after the other using a digital still camera? Even if the camera is powered up and ready to go, you miss shots during the noticeable delay while the camera takes its time to capture, process, and store each image on a memory card.
Some cameras allow you to take a series of 5, 7, or maybe 10 shots before the camera pauses. Of course, this just delays the inevitable, since there is an even longer wait as the camera processes and stores the whole series. But Tokyo-based Kyocera Corp. (http://www.kyocera.com) offers a feature in at least three of its cameras that lets you take those rapid-fire digital shots.
RTune is Kyocera's name for the technology, but the chip set that delivers the speed is called CleanCapture by its developers at NuCore Technology Inc., a six-year-old Sunnyvale, Calif., start-up with a research group in Tokyo (http://www.nucoretech.com).
CleanCapture is a two-chip set for image processing that sits between the image sensor and the memory card. It does in special-purpose hardware what other cameras do in software. Therein lies the speed. "What the chips do in 20 milliseconds, regular digital cameras do in 2 seconds," says Seiichiro Watanabe, NuCore's founder and chief technical officer.
In a typical digital camera, an image sensor captures a pixel-by-pixel image as an analog signal, which is then converted to a digital signal. In turn, the digital signal is processed and compressed, then stored in memory.
The NuCore chips provide analog-to-digital conversion using an analog front-end chip and a digital back-end chip. The analog chip enables pixel-by-pixel color correction--white-balance adjustment in photography parlance, or noise reduction in EE-speak--as it processes analog pixel values fed to it by the image sensor. It then converts them to digital values and feeds them to the digital chip.
The digital chip includes an image-processor hardware block. Within the block are hardwired pipelines for moving the digital signals. All image processing is done in this block at 75 megapixels a second, fast enough to compress still images in the popular JPEG file format without an external buffer memory.
With the noise cleaned up before the digital-processing stage, the initial data volume of a picture is smaller and thus more easily compressed. Noise in a signal is treated as data during compression, whether by this chip or any other, and it reduces compression efficiency. According to Watanabe, as a result of the early noise reduction, JPEG files emerging from NuCore's chips are half or even a third the size of those processed conventionally.
Smaller image files are good news for camera-wielding consumers. The improved compression will free up more memory for the additional shots they've just taken.
So just how fast is one of Kyocera's RTune cameras? Burst capture on most digital still cameras is only about 1.6 frames per second. The S3R with RTune delivers 3.2 megapixels at 3.1 fps until the camera's Secure Digital memory card is full.
Shutter speed comes at a price, though. To deliver those shots, RTune requires a high-speed SD Memory Card, one that writes at 8-10 MB/s. That feature can add US $25 or more to the price of a $35 card, though prices are dropping. The S3R camera itself is currently on European retailers' shelves for around ¤340. It is expected in U.S. stores for about $400.
While the S3R is the latest Kyocera camera to offer burst-capture photography, it isn't the only one. The 5-megapixel S5R and 3.2-megapixel SL300R have used NuCore's chip since their debut on Japanese store shelves last year, just 10 months after initial silicon tape-out (the first step in chip manufacturing). Both are available worldwide. The SL300R goes for $317 to $399, while the S5R is $405 to $549, depending on which Internet retailer you choose.