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NuCORE Chip Set First to Deliver
3-CCD Color Quality to 1-CCD Cameras at 50 Megapixels Per Second
Enables First True Hybrid Digital Still/Video Cameras
SANTA CLARA, Calif. – July 26, 2000 – The industry’s first chipset that delivers 3-CCD color quality to 1-CCD cameras at 50 megapixels per second has been introduced by NuCORE Technology, Inc. The two chips are the NDX-1250TM analog front-end and the SiP1250TM Smart Image Processor (SiPTM). No other combination of chips comes close to NuCORE’s 50 megapixel-per-second image processing with 12-bit resolution.
Both chips employ sophisticated, proprietary algorithms to deliver visually superior image quality, high resolution and wide dynamic range with just a single CMOS sensor or CCD (charged coupled device – the sensor that captures the picture). NuCORE’s chipset is ideal for high-end consumer applications as well as professional applications, which typically require three separate signal processing chains for Red (R), Green (G) and Blue (B) to attain this level of image quality. Through its patented NDXTM process, it amplifies R, G and B separately even though the three signal processing chains are minimized to one, reducing overall cost, size and power consumption.
This chipset lets designers build a hybrid camera – a single consumer device that can be used as a high-quality still camera and a high-quality video camera. It has never before been possible to build one camera that can acquire, enhance, compress, display and store 4-megapixel silver-halide-quality, digital still images continuously at a rate of 12 per second (“paparazzi-like”) and 1.3-million-pixel video at 30 frames per second with 12-bit accuracy.
“Having one camera that can serve both functions has been regarded as the ‘holy grail’ of digital photography,” stated NuCORE CEO Joe Raffa. “It’s what digital camera makers have been trying to build, unsuccessfully. Either they build a still camera that takes a few seconds of low-resolution motion, or a motion camera that takes poor quality stills that are unsuitable for photo printing. No other chip maker has been able to give them a solution that can do both, until now.”
“We are very happy with the performance of these new chips in areas such as image quality, dynamic range and resolution at 30 frames per second. With NuCORE Technology, we will able to offer a 12-bit solution in our camcorder, providing four times the image quality of our current offering," said Keizo Kohno, Chief Engineer, System R&D center, Professional Products, Systems and Network sector, Victor Company of Japan, Ltd. (JVC).
Additionally, NuCORE designed this chipset to minimize the power requirements to enable the design of smaller, lighter cameras. Initial tests prove that NuCORE’s two-chip solution provides 3x to 5x the battery life of all other solutions.
The Hybrid Camera Challenge
Until now, camera makers have had to make critical trade-offs. When designing a still camera, they could increase the number of pixels per photo by capturing the pixels quickly, then processing (adjusting the color, compressing, and doing a host of other functions) after the fact. That’s why users must wait a while between shots with megapixel cameras. NuCORE’s chipset solves this problem by processing the images in real time. Cameras built with NuCORE’s chipset can capture 12 images per second at four megapixels.
To get the 30-frames-per-second speed required for full-motion video, designers have to trade off the number of pixels captured in any one frame. Most video camcorders record images between 300,000 and 600,000 pixels per frame. While this resolution is perfectly acceptable for display on most conventional televisions, when the user tries to capture a still frame for a photograph, that still frame is not of high enough resolution for acceptable photo printing. With NuCORE’s solution, video images can be recorded at over a million pixels per frame, making it much easier to obtain excellent still images from existing footage and much better for displaying on next-generation high-definition television sets.
A Total System Solution
While the two chips can be designed-in separately and each provides industry leading features, the optimal result comes from the unique combination of features in this total solution. By developing both chips together, NuCORE was able to take a fresh look at all of the functions required and develop the optimal partitioning of analog and digital processing. This flexibility to be creative in moving functions from the digital to the analog domain and vice versa, as well as moving functions up and down the image processing chain, gave NuCORE an opportunity to overcome some barriers other chip makers have not been able to cross and get spectacular results.
For example, NuCORE moved much of the color balancing from the digital post-processing chip to the analog front-end chip. By color balancing the image immediately, in analog, NuCORE is able to get much higher image quality.
Competing designs combine one company’s analog front-end with another company’s (or proprietary) digital processing unit that uses off-the-shelf digital signal processors or embedded cores and don’t come anywhere near the speed, resolution and dynamic range of this matched chipset.
Additionally, the speed of all other solutions is hampered by having to implement most (usually over 70 percent) of the image processing algorithms in software, rather than in hardware. NuCORE is the only company that implements all its image processing algorithms in custom-designed hardware in both chips. And all image processing algorithms are not the same. NuCORE believes it has implemented the most comprehensive set of algorithms in the digital camera industry, providing the highest image quality.
Yet by making its hardware implementation register programmable, NuCORE makes it easy for the camera makers to personalize their own camera designs through tuning, a process that lets one camera maker set colors for warmer tones, for example, while another will tune for a different tonal look.
The NDX-1250 – A High-Speed Analog Front End
The NDX-1250 is a complete CCD and CMOS sensor image digitizer that includes a high-speed differential correlated double sampler (CDS), black-level auto-calibration circuitry, a programmable gain amplifier (PGA), and a 12-bit analog-to-digital converter (ADC). The CDS removes the spurious low-frequency noise from the sensor signal by taking two samples of the sensor output, one with the signal data present and one without. By subtracting the two samples, any noise that is common or correlated to both of the samples is removed. This is performed on a pixel-by-pixel basis at 50 million pixels per second. Analog black level calibration is performed for each color separately. Color balancing, which usually only is performed after the conversion to digital, is performed in analog in this chip to help increase the dynamic range.
The dynamic range of an image sensor is significantly less than that of a human eye. That’s why professional cameras have, until now, used three sensors to capture all of the details in both the brightest and the darkest parts of a scene. In most single-sensor cameras, the dynamic range problem becomes a huge issue because it cannot easily be made up in software in post processing. The dynamic range is a lost opportunity if it is not captured in analog up front.
NuCORE’s patented NDX approach normalizes and changes the gain, pixel by pixel, every 20 nanoseconds to reach the 50 megapixel-per-second throughput. This on-chip dynamic range expansion technique allows the NDX-1250 to, in effect, process R, G and B separately, avoiding the problem other analog front-end chips have because processing one color will then affect the processing of the next color. When processing green, for example, and then processing blue, there can be a 10x difference in amplitude between the two colors, making the blue come out almost transparent without further correction.
The NDX-1250 is the only chip that implements decimation in analog. NuCORE’s patented decimation preserves battery life by eliminating unnecessary pixels. For example, most camera LCDs can only display images at 320 x 240 or 153,600 pixels. By decimating the unnecessary pixels up front, in analog, when the camera is in view-finding mode, only 153,000 instead of 4 million pixels need to be moved through the complete camera system. Decimation can provide up to a 45 percent power savings compared to full-performance operation. In all other designs, decimation is done in the digital processing chip.
The SiP-1250 Smart Image Processor
The SiP-1250, an optimized pipelined processor designed for image processing, is an ideal companion for the NDX-1250. Virtually all of the necessary functions and image processing algorithms are implemented in register-programmable hardware for maximum speed. The designer can tune the hardware to give the camera a unique look and feel, giving the image output the desired sharp vs. soft or cool vs. warm look desired, just as is done with a traditional analog camera by selecting different types of film, shutter speeds and F-stops. All other competing solutions use general-purpose core microprocessors or digital signal processors and require that a lot of the imaging-specific algorithms be implemented in software, slowing down the overall camera and adding to power consumption.
The SiP-1250 also does not require any cache memory to store images to reach its full throughput. Most competing solutions require that cache memory is employed, increasing the power consumption per picture.
In addition to the standard image processing functions such as Bayer-to-RGB conversation, color correction, gamma correction and YC conversion, the SiP-1250 includes proprietary algorithms that provide superior image quality:
- Skin tone detection. The SiP-1250 includes algorithms that detect skin tone so the camera designer can implement any desired compensation on the fly.
- Adaptive filtering. The SiP-1250 uses adaptive filtering to change the algorithms locally, as it processes the image in real time. Camera designers can use this capability in combination with skin tone detection to adjust skin color under different lighting. For example, under fluorescent light skin tones tend to turn bluer while under sunlight skin appears redder.
- Adaptive edge enhancement. The SiP-1250 includes unique algorithms to selectively make edges more pronounced, sharp and crisp. The chip can detect areas that tend to wash out based on several data points and compensate in real time.
- False color suppression. The SiP-1250 compensates for color distortions that can often appear in images from single-sensor cameras with mosaic color filtering. This is a problem with thin objects, such as a hair, that may be no more than one pixel in width. Another example of a problem occurs when photographing crystal glass against a white background.
After image processing and enhancement, the images can be compressed in a variety of ways. JPEG image compression can be applied in various degrees set by the user. Moving images can be compressed using the motion JPEG standard. Additionally, data can be sent out to an external CODEC for DV or MPEG compression.
The professional quality video encoder built into the SiP-1250 lets the user preview captured images on television. The video encoder supports the NTSC and PAL standards. For professional video camera designers, the “GEN-LOCK” clock synchronization function is built-in. In addition, the SiP-1250 includes the standard camera interfaces, such as USB, hard disk drive, and flash memory.
A Low-Power Solution
By implementing algorithms in hardware rather than software, NuCORE significantly cuts overall power requirements for its chipset. Additional built-in features, such as horizontal decimation, cut power in stand-by modes. Power consumption of the NDX-1250 is less than 120 mW at 50 megapixels per second and less than 72 mW at 30 megapixels per second. Power consumption for the SiP-1250 is less than 450 mW at 50 megappixels per second and less than 270 mW at 30 megapixels per second.
Full System Support
NuCORE supplies a robust camera system-level reference design and API based on the Hitachi SH2 microcontroller and the µItron 3.0 embedded operating system. Other processors also are supported. For the SiP-1250, NuCORE supplies necessary APIs for USB, LCD display, JPEG, autofocus and autoexposure. NuCORE supplies digital camera APIs such as zoom control, flash control, button control, etc. NuCORE also supplies utilities and diagnostics. To further speed the design process, NuCORE supplies easy-to-use PC-based tuning tools that provide the camera designer with a significant level of customization.
Pricing and Availability
The NDX-1250 is packaged in a 48-lead TQFP package. Sample quantities are available now. It is priced at $15 in quantities of 100,000.
The SiP-1250 is packaged in a 256-ball BGA package. Sample quantities will be available this November. It is priced at $40 in quantities of 100,000.
NuCORE Technology, Inc., is developing scalable, turnkey solutions for innovative imaging devices. The company will enable OEMs to offer professional quality imaging in consumer products. Visit NuCORE at www.nucoretech.com.
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NDX and SiP are trademarks of NuCORE Technology, Inc. All other brands or products are the trademarks or registered trademarks of their respective owners.
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