Merging CMOS and image processing
Oct 27, 2000 at 04:00 GMT
According to an article in EETimes the race is on to merge image processing and CMOS sensor into one device, "Some companies are going for an extremely high-quality, high-price CMOS sensor market, while others are going for lower-priced products. Vendors need to differentiate, but it's getting more difficult for them to define their own niche," In-Stat's O'Rourke said.
Race is on to merge image processing, CMOS sensor
By Junko Yoshida, EE Times
SAN MATEO, Calif. The competition in CMOS image sensors has turned ferocious, pitting established giants such as Agilent Technologies Inc. against such smaller upstarts as IC Media Corp.
The combatants are marshaling integrated solutions that will pair front-end sensors with back-end imaging processors in a bid to lower the cost, size and power consumption of digital imaging systems.
Agilent (Palo Alto, Calif.), the largest CMOS image-sensor supplier in the industry, is ready to introduce a family of image processor chips that is designed to work well with its own CMOS image sensors. The rollout marks Agilent's first step in a self-transformation from a "pure sensor play to a system-level digital-imaging solution provider," said Jason Hartlove, business unit manager at Agilent's Imaging Electronics Division.
Meanwhile, a little-known startup called IC Media (San Jose, Calif.) is introducing its first CMOS VGA image sensor and setting a new low price point for PC cameras. At a time when most CMOS VGA sensors are produced in a 0.5-micron process, IC Media is mass-producing its CMOS sensor using United Microelectronics Corp.'s 0.35-micron process, said Jim Li, executive vice president of IC Media. The finer geometry means a lower cost and allows camera OEMs to use a quarter-inch optical system rather than the current one-third-inch optics with the image sensor. "That translates into a more compact design and cost savings at the system level," Li said.
So far, Agilent is the only other vendor that has shifted to 0.35-micron geometry; the company is announcing two CMOS image sensors Oct. 30 in CIF and VGA resolutions.
Down the road
Many CMOS sensor companies see the mobile/cell phone market as the key to future business and are racing to find partners or develop their own technologies internally. Their goal is to offer both CMOS image sensors and image-processing solutions now, along with a road map to integrate both onto a single chip. "Agilent's move definitely sends a warning signal to the market, that sensor vendors need to get more involved in the back-end image-processing business," said Brian O'Rourke, senior analyst at Cahner's In-Stat Group.
Such a trend is already evident. STMicroelectronics, for one, took the first step by acquiring VLSI Vision Ltd., a well-known CMOS image-sensor company, in early 1999. Through the acquisition of Sierra Imaging Inc. earlier this year, Conexant Systems Inc. also positioned itself to offer digital camera manufacturers complete camera solutions combining Sierra's back-end digital-image processors and image-management software with Conexant's front-end CMOS image sensors.
Similarly, Zoran Corp. earlier this year acquired PixelCam Inc., a privately held maker of megapixel CMOS image sensors. Zoran's ambition is to become a one-stop shop for OEMs to source both image sensor and image compression solutions.
Not every company is following the acquisition and merger route, however. Photobit Corp., a CMOS image-sensor technology innovator, is developing its own fully digital color processor. Photobit designed the processor to do color-processing functions including white balance, color correction and others, but with no standard image compression, said Michael Kaplinsky, the Photobit business unit manager responsible for mobile applications. Such a fully digital color processor will be integrated with Photobit's own CMOS sensor on a single "camera-on-a-chip" for mobile phone applications, he said.
Image sensor/image processor integration is essential for cell-phone and camera applications, due to system requirements for smaller size and low power consumption, Kaplinsky said. In the first quarter of 2001, Photobit will roll out a tiny camera-on-a-chip that operates at 2.7 volts with power consumption of less than 50 milliwatts, he said.
For now, however, the volume market for CMOS image sensors centers on PC cameras and digital still cameras. According to IDC analyst Ron Glaz, 6 million units of CMOS image sensors are expected to ship in the PC camera market in 2000 and 5 million for the digital still camera market.
Like Photobit, Agilent, too, is moving into the image processor market using internal resources. The company is introducing two image-processing chips HDCP-2000 for USB-based PC cameras and HDCP-2010 for handheld computers, cell phones and notebook computers. Designed for VGA- and CIF-resolution cameras, both chips provide complete sensor control, including autoexposure and auto white-balance functions as well as true JPEG compression with programmable quantization tables.
Some PC camera IC solutions available on the market today offer minor compression on the chip, which allows the raw imaging data that a sensor captures to be compressed enough to travel over a Universal Serial Bus. In such a design, the rest of the image-processing functions, such as color correction, white balance and full image compression, are carried out on a PC.
Agilent engineers nixed that approach, Hartlove said, "because you lose the quality of data through such a minor compression, which could also introduce artifacts, and is further enhanced in the image processing done on the PC later."
Agilent's HDCP-2000, priced at $7.95 in 10,000-unit orders, features a USB interface to communicate imaging data over that bus, while the HDCP-2010 offers fully processed image output in either direct JPEG or YUV formats for parallel or serial output. The HDCP-2010, also priced at $7.95 in 10,000-unit orders, is well-suited to mobile applications because it comes in a much smaller 48-pin micro-BGA package and consumes less than 100 mW.
Both of the Agilent imaging processors feature a sensor interface peculiar to the Hewlett-Packard HDCS family of CMOS image sensors. "Our image processors fully take advantage of the characteristics of our own image sensors and offer a complete image-processing pipeline," Hartlove said.
Photobit's Kaplinsky noted that matching image processors to specific CMOS sensors brings advantages beyond the ability to offer a one-stop shop for digital imaging solutions. "You could design image processors to reproduce the best possible results, by leveraging the intimate knowledge of your own sensors' dynamic range and spectrum characteristics," he said.
In addition to its two image-processing chips, Agilent is also launching HDCP-3200, a complete digital-image processor designed for a full-featured digital still camera. A Motorola Coldfire 32-bit core running at 144 MHz and embedded on-chip provides flexibility for adding new features and customizing a design. The chip offers a high-performance hardware image pipeline and JPEG codec, the company said.
"All the numeric-intensive tasks are done in hardware, rather than running software on Coldfire," Hartlove said, "so that the chip consumes a lot less power, and it runs much faster for consecutive shooting."
The new HDCP-3200 is based on the HDCP-3000, which was originally used in HP-designed digital cameras. The Agilent image processor, designed for midrange to low-end digital still cameras, can be used with any type of sensors CCD or CMOS. Available now, it is priced at $17 in lots of 10,000.
Meanwhile, the CMOS image-sensor market grows increasingly crowded. "Some companies are going for an extremely high-quality, high-price CMOS sensor market, while others are going for lower-priced products. Vendors need to differentiate, but it's getting more difficult for them to define their own niche," In-Stat's O'Rourke said.
IC Media's first commercial product, ICM105A, is a CMOS image sensor that incorporates a 640 x 480-sensor array that can capture still or full-motion video at up to 30 frames/second and convert the images to digital data. It includes a 9-bit analog-to-digital converter that performs correlated double sampling to improve image quality.
Ben Wu, president and chief executive officer at IC Media, said the company achieved a couple of things by moving to a 0.35-micron process from 0.5-micron CMOS, where availability is increasingly tight these days. "We've not only secured an ample supply for our customers, but also lowered the cost," Wu said. The ICM105A uses 6 x 6-µm digital sensors, which in effect offer better quality than many 8 x 8-µm sensors based on a 0.5-micron process, claimed executive vice president Li. "It turns out that the 0.35-micron process offers more accurate, better alignment."
Not to be outdone, Agilent is launching two new CMOS image sensors of its own: HDCS-2020 for VGA and HDCS-1020 for CIF resolution. Both are available in volume now, the company said. The VGA version integrates a 10-bit A/D and offers 15 frames/s, while the CIF device provides an 8-bit A/D and handles 30 frames/s. Both sensors are based on a high-sensitivity, low-noise design, making it possible to capture images in a wide variety of lighting conditions, Hartlove said.
Thanks to a switch to a 0.35-micron process, the Agilent CMOS image sensors use a 7.4-micron pixel pitch. "We maintained the high-performance image quality of our sensors while shrinking the die size by implementing dark-current optimization," he added.
Compared to Agilent, IC Media, the newcomer, is pricing its CMOS image sensor much more aggressively. IC Media's CMOS VGA image sensor is priced at $7.35 in 10,000-unit orders, while Agilent's CMOS VGA sensor is offered at $12.25 and its CMOS CIF sensor at $7.95.
Pointing to market demand, Wu said IC Media aims to offer solutions that integrate its CMOS sensor with internally developed image-processing blocks. He called the company's ICM512D a system-on-chip that integrates a CIF-resolution CMOS sensor, color processing and NTSC encoder, with a TV output. Built in a 0.5-micron process, it is priced at $10.50 in lots of 10,000.