Triple-decker chip provides full color for every sensor pixel: Foveon X3 array offers many advantages for digital camera designs.A new type of digital imaging sensor was introduced at PMA PMA (papillary-marginal-attached),
n a system of epidemiologic scoring of periodontal disease devised by Schour and Massler in which the symbols denote the areas involved in gingival inflammation.
PMA Progressive muscular atrophy 2002 by Foveon Inc., Santa Clara Santa Clara, city, Cuba
Santa Clara (sän`tä klä`rä), city (1994 est. pop. 217,000), capital of Villa Clara prov., central Cuba. , Calif. (www.foveon. com), which delivers higher and more accurate image quality without producing color artifacts artifacts
see specimen artifacts. . Employing a three-layer sensor, the radical Foveon X3 technology captures red, green, and blue light at each and event pixel point, eliminating the need for color interpolation interpolation
In mathematics, estimation of a value between two known data points. A simple example is calculating the mean (see mean, median, and mode) of two population counts made 10 years apart to estimate the population in the fifth year. . It produces better color and sharper images than the side-by-side, checkerboard-style RGB (Red Green Blue) The computer's native color space, which is the color system for capturing and displaying images. RGB was derived from our own perception of color because human eyes are sensitive to red, green and blue (see trichromaticity). mosaic arrays.
The new CMOS-based sensor stacks sensitive photo detectors that measure color at three levels throughout a single silicon wafer, providing every pixel in the array with the opportunity of recording the subject in full color, without the use of a color mosaic filter or a three-chip multi-shot imaging system.
"The Foveon X3 represents the most significant breakthrough in digital camera technology since the invention of CCDs more than 30 years ago. This new technology combines the immediacy and excitement of the digital photography experience with the quality that exceeds what consumers have previously come to expect from film," comments Jim Lau, Foveon CEO (1) (Chief Executive Officer) The highest individual in command of an organization. Typically the president of the company, the CEO reports to the Chairman of the Board. .
"Current image sensor technology has not enabled digital cameras to realize their full potential. We believe the breakthroughs of the Foveon X3 technology will form the foundation of a new generation of digital cameras in all classes," Lau continues.
Nearly all other color sensor designs record only one color per pixel and are significantly more susceptible to unpredictable color artifacts, which produce color moire Pronounced "mor-ray" and spelled "moiré." In computer graphics, a visible distortion. It results from a variety of conditions; for example, when scanning halftones at a resolution not consistent with the eventual printed resolution or when superimposing curved patterns on one and the "Christmas tree Christmas tree
Evergreen tree, usually decorated with lights and ornaments, to celebrate the Christmas season. The use of evergreen trees, wreaths, and garlands as symbols of eternal life was common among the ancient Egyptians, Chinese, and Hebrews. light" effect in digital images. The innovative Foveon X3 technology is also the first to incorporate Variable Pixel Size (VPS (1) (Vectors Per Second) The measurement of the speed of a vector or array processor. See vector, vector processor and array processor.
(2) (Virtual Private Server) See OS virtualization. ) into an image sensor, which enables the design of a new class of consumer products--a dual-function digital still camera/camcorder that will excel in image quality for both capture modes, according to the company.
One physical property of silicon is that light of different wavelengths is absorbed at different depths in the material. Blue light is absorbed near the surface, green light is absorbed at a lower level, and red light is absorbed at the deepest level. The sensor design takes advantage of silicon's natural color-separating properties. The Foveon X3 sensor The Foveon X3 sensor is a CMOS image sensor for digital cameras, designed by Foveon, Inc. and manufactured by National Semiconductor and Dongbu Electronics. has three photo detectors located in each pixel at different depths, and they measure the photo-generated current at each level. From this measurement, color information for the image is obtained after the three signals are converted into digital data and processed by Foveon's image processing software.
The Foveon X3 sensor design provides several unique benefits:
* Image sensors are much less susceptible to color artifacts, compared to single-layer sensors. The Foveon chip captures three colors per pixel, while mosaic image sensors capture only one color per pixel. Current CCD CCD
in full charge-coupled device
Semiconductor device in which the individual semiconductor components are connected so that the electrical charge at the output of one device provides the input to the next device. and CMOS (Complementary Metal Oxide Semiconductor) Pronounced "c-moss." The most widely used integrated circuit design. It is found in almost every electronic product from handheld devices to mainframes. color image sensors have one layer of monochromatic monochromatic /mono·chro·mat·ic/ (-kro-mat´ik)
1. existing in or having only one color.
2. pertaining to or affected by monochromatic vision.
3. staining with only one dye at a time. photo detectors, with one photo detector per pixel. To capture color, the array is organized in a mosaic pattern mosaic pattern Cervix A colposcopic defect at the transformation zone of the cervix–atypical when the cervix is covered by 3% acetic acid; the fields of sharply demarcated 'mosaic' are separated by reddish–vascularized borders; MP may signify epithelial resembling a three-color checker-board with each pixel assigned only one color--red, green, or blue. Since only one color is captured, the sensor employs complex mathematical algorithms to interpolate See interpolation. the remaining two-thirds of the colors not captured.
* The new sensor produces sharper images, since color interpolation and the use of the mosaic filter results in loss of image detail. The company reports the Foveon X3 sensor has twice the sharpness of a mosaic image sensor with comparable pixel count.
* The Foveon X3 sensor gathers more light and can operate successfully at lower illumination levels. In a mosaic sensor, each pixel collects only one color of three, or roughly one-third of the available light. The remaining two-thirds of the incident light is absorbed by the color filter and not used to produce a photograph.
* Since the Foveon X3 sensor eliminates the need for image reconstruction, it is possible to manufacture less intricate digital still cameras. For example, color interpolation adds cost and complexity to digital camera design and operation, as well as increasing the time delay between the shutter release and the actual capture of an image. These delays--due to the digital camera's processing requirements--can easily result in the difference between snapping a great picture and missing an important moment. The new sensor will simplify camera designs and improve "click to capture" performance.
* The Foveon X3 chip design also enables the development of a new hybrid class of digital cameras, which combine both still imaging and digital video capture at high resolution, due to the capability of the Variable Pixel Size (VPS) feature. VPS allows several neighboring pixels to be averaged together in "blocks" to obtain the effect of a larger area pixel. Among its virtues, VPS allows higher equivalent ISO (1) See ISO speed.
(2) (International Organization for Standardization, Geneva, Switzerland, www.iso.ch) An organization that sets international standards, founded in 1946. The U.S. member body is ANSI. sensitivity at lower resolutions without sacrificing low noise levels, as well as offering flexible video capture at a variety of resolutions.
The combination of digital video and sharp, high-quality still photography in the same camera, is a prime application goal for the Foveon X3 technology. "Parents, for example, can use this new type of camera to capture video of their child playing soccer. Midway through video recording, they can press a shutter button to capture a high-resolution photograph, and then seamlessly continue recording video.
Security applications could also benefit from this high-quality, dual-mode capture capability. Foveon X3-enabled airport security cameras could record video for general surveillance and capture high-resolution still photographs targeting suspected individuals or at timed intervals," Lau suggests.
"The photographic detail and color that can be achieved with this new technology is unsurpassed," Lau states. "Pixel for pixel, Foveon X3-based digital cameras will deliver higher-quality images than any other sensor."
Like all CMOS-based sensors, the Foveon X3 sensor has lower power requirements compared to similarly sized CCD sensors. The company describes the chip's power needs as "ultra low," due to advanced CMOS processing technology. For example, the power consumption of the 20.7-by-13.8mm chip is less than 50mW during readout (1) A small display device that typically shows only a few digits or a couple of lines of data.
(2) Any display screen or panel. , less than 10mW in standby mode, and less than 100[mu]W in power down mode. Again, as with all CMOS chips, the X3 sensor has substantially greater resistance to specular highlight "blooming" than CCD sensors.
Several different sizes of Foveon X3 chips are in the works. The first production model is a 2,304-by-1,536-by-3pixel array (3:2 aspect ratio) that measures 20.7-by-13.8mm (25mm diagonal). The sensor has an equivalent ISO 100 sensitivity in full-resolution mode.
Sigma Corp. is the first to incorporate this imaging chip into a camera model. The new Sigma SD9, an interchangeable lens digital camera built on a Sigma 35mm SLR (1) (Scalable Linear Recording) A line of magnetic tape drives from Tandberg Data that evolved from the QIC Data Cartridge format. See QIC.
(2) (Single Lens Reflex) A camera that uses the same lens for viewing and shooting. body (www.sigma-photo.com), was introduced at PMA 2002. The camera offers a RAW data recording setting, so the highest picture definition and compact file size are possible through lossless compression A compression technique that decompresses data back to its original form without any loss. The decompressed file and the original are identical. All compression methods used to compress text, databases and other business data are lossless. of RAW data.
Available during the third quarter of this year, a 6.4-by-4.8mm sensor with 1,344-by-1,024-by-3-pixel resolution is scheduled for 0.5-inch optical formats. Other X3 sensors are also being developed.
The company calls the technology "highly scalable," and it could be used in the design of small, mid-range, and large image sensors that would produce smaller file sizes than mosaic-pattern chips for the same size high-quality images.
"Today's CCD and CMOS image sensors detect only one of the three required colors at each pixel and must mathematically estimate the remaining two colors not detected. By capturing three colors at every pixel instead of one, Foveon X3-based cameras have measured information for all three colors. This results in high-quality photographs with fewer pixels, because the pixels are based on real measurements. Fewer pixels result in smaller file sizes, allowing digital camera users to send a higher-quality photograph more quickly through an e-mail message. It also means more digital photos can be placed on a digital camera storage See memory card. card," a Foveon document explains.
A Foveon press release also states "Photographs from the Sigma SD9 camera can be enlarged to 30 inches, exceeding the quality of 35mm film." This claim was reported by ABC TV news anchor Peter Jennings in a network prime time broadcast, where he also displayed high-quality images produced by the three-deep sensor array.
Dr. Carver Mead, a pioneer in solid-state electronics and VLSI VLSI: see integrated circuit.
(1) (Very Large Scale Integration) Between 100,000 and one million transistors on a chip. See SSI, MSI, LSI and ULSI.
(2) (VLSI Technology, Inc., Tempe, AZ, www.semiconductors. design, founded Foveon in 1997. Recent accomplishments include development and production of an ultra high-resolution professional portrait studio digital camera and the 16.8-megapixel CMOS image sensor, as well as the new Foveon X3 full-color image sensor. The privately held company's investors include National Semiconductor Inc., Synaptics Inc., and New Enterprise Associates.