FireWire pushes plug-n-play imaging
Numerous computer, peripheral, board, and camera vendors are promoting product and system interoperability via the IEEE 1394 standard.
In the 1980s, Apple Computer (Cupertino, CA) developed FireWire, a serial bus interface that interconnects computer peripherals, storage systems, and consumer electronics. Standardized by the Institute of Electrical and Electronics Engineers (IEEE) as IEEE 1394, the interfaces currently support data rates to 400 Mbits/s. To further advance the FireWire standard, the Standards Board of the IEEE Standards Association (Piscataway, NJ) has recently approved IEEE Standard 1394b—High-Performance Serial Bus-which amends the previous IEEE 1394—1995 and IEEE 1394a-2000 standards.
The IEEE 1394b standard upgrades the prior standards by permitting signaling to 3.2 Gbits/s, extending signaling distances to 100 meters, and maintaining backward capability with the existing versions. It also complies with key features of the two earlier standard versions, such as point-to-point connectivity, plug-and-play changeability, and guaranteed timing. More important for the machine-vision and image-processing industry, the updated 1394b accommodates high-megapixel densities and increased color depths.
Currently, solid-state-camera manufacturers are using this interface to replace traditional frame grabbers and reduce costs in machine-vision system designs. These characteristics enable camera vendors, such as Basler AG (Ahrensburg, Germany), MetaControls (Morrisville, NC; now part of Adept Technology Inc. (San Jose, CA), and Sony Electronics (Park Ridge, NJ), to offer camera-based products based around the IEEE 1394 standard (see tables beginning on p. S11).
FireWire for vision
Already, FireWire developments are emerging in machine-vision applications. One company, Zevac (Solothurn, Switzerland), has designed its Onyx 32 semiconductor-placement system based around the IP-1000 multifunctional positional system originally developed by Infotech Automation (Solothurn, Switzerland; seeVision Systems Design, July 2001, p. 8). During operation, the Onyx system automatically picks, inspects, and places flip-chip packages on printed-circuit boards (PCBs).
"Instead of using a bulky wiring harness to carry data, input/output, and power signals around the system," says Robert Black, chairman of Infotech's sister company Meta Controls, "the IP-1000 system uses a single IEEE 1394a (or FireWire) cable." To image the flip-chip package before placement, a FireView-1 CCD-based digital camera from MetaControls captures 640 × 480 × 24-bit images. These images are then transferred to the host computer over the FireWire bus using PC-resident Visual Machines software from Infotech.
Since acquiring MetaControls, Adept has announced a series of self-contained, pre-engineered amplifier and motor packages that are preconfigured to work with the company's SmartControllers, which are all based on IEEE 1394 technology. Each Adept Servo Kit consists of an Adept SmartAmp with a matched ac servomotor, absolute encoder, amplifier mounting bracket, and documentation. Components such as power and interface cables, remote I/O kit, power-distribution unit, and cable accessories are available as options. The kits are based on Adept's SmartAmp technology and provide true plug-and-play servo compatibility with the company's SmartController products.
Several months ago, Industrial Control (Eindhoven, The Netherlands) also introduced FireWire industrial I/O products under the name FirePoint for machine-vision and I/O applications. These I/O modules, based on the IEEE 1394 standard, enable OEM machine builders and system integrators to offer a complete machine-control system—motion, vision, and I/O on a single FireWire machine backbone. The FirePoint products are set up in a modular system, available in various models for volume OEM clients.
But it's not just in machine-vision applications that FireWire cameras are being deployed. At the Gray Cancer Institute (Northwood, Middlesex, UK)—a UK-funded cancer-research institute-the advanced technology development (ATD) group is working on including single-cell gel electrophoresis (or comet assay) for looking at the damage to DNA caused when it has undergone certain treatments (seeImage Processing Europe, July/August 2002, p. 12).
In this semi-automated system, the technician must position and focus each individual comet assay within the center of the microscope's field of view. The remainder of the process is automated, however, and results in an analysis rate of approximately 200 to 300 comets/hour. In the fully automated system, this image manipulation is not needed due to the higher dynamic range of the Hamamatsu Photonics UK (Welwyn Garden City, Herts, England) 12-bit ORCA-ER camera used to capture the comet image. This cooled CCD camera provides an extended range of 1344 × 1024 pixels and full remote control from the connected PC via an IEEE 1394 interface. In addition to obtaining a wider dynamic range, the ATD group chose FireWire because it eliminates the need for a frame grabber board in the PC.
The processes of comet location and focusing are performed in the fully automated system by an inverted Nikon (Melville, NY) Eclipse TE300 microscope using a motorized SCAN IM 120 × 100 microscope stage from Märzhäuser (Wetzlar-Steindorf, Germany). This setup sequentially scans the test slide in steps while the images are captured. Captured images are sent to the PC, and a focus indicator is then produced using a fast-Fourier-transform approach. Feedback from the PC triggers the microscope lens to alter its position before a new image is captured. This iterative procedure continues until a highly focused image is captured.
Other biomedical researchers are also taking advantage of the low cost of FireWire-based cameras and peripherals. At the direction of a global pharmaceutical company, VayTek (Fairfield, IA) has developed an automated microscopy system that incorporates microscope and antiblurring algorithms with a confocal adapter to provide data comparable to more-expensive laser-scanning confocal microscopes (seeVision Systems Design, October 2001, p. 29).
This microscopy system collects stacks of between 40 and 50 pictures along the z-axis for each of 36 locations to estimate the arterial volume in a 3-D tissue sample. During operation, a mercury lamp inside the Olympus (Melville, NY) AX70 research system microscope excites a dye that is attached to the arterial walls of a rat's retina. During excitation of the sample, a Peltier-cooled Retiga 1350EX camera from QImaging (Burnaby, Canada) attached to the microscope takes upward of 5400 images per slide.
Originally developed by Triptar Lens Co. (Rochester, NY) for Optem Avimo Precision Instruments (Fairport, NY), an Optigrid desktop confocal-microscope controller gives the Olympus AX70 microscope the ability to collect confocal 2-D cross sections of the sample. A host PC with a Windows-based 800-MHz Pentium III processor running VayTek's RetinaScan and Triptar's Image Pro driver software controls the Optigrid microscope. Other computer characteristics include a 256-Mbyte RAM, a 60-Gbyte hard drive, a 21-in. Sony monitor, and RS-232 and FireWire ports.
Also recognizing the advantages of FireWire interfacing in the scientific/biomedical imaging market, Media Cybernetics Inc. (Silver Spring, MD) and Vitana Corp. (Ottawa, Ont., Canada) are collaborating on Media Cybernetics' Evolution LC camera kits. These kits combine Media Cybernetics' Image-Pro software with Vitana's MegaPixel FireWire PixeLink cameras that use the FireWire interface to eliminate the need for frame grabbers.
According to the 1394 Trade Association (Grapevine, TX), more than 170 vendors are producing area-array cameras, interfaces, hubs, and peripherals in adherence to the IEEE 1394 standard. As an imaging standard, IEEE 1394 will more likely be used in applications that require standard video resolutions and rates, such as microscopy, medical, and scientific applications. Other higher-speed interfaces such as Camera Link will more likely be used for industrial applications that require high-resolution and high-rate area- and linescan cameras (see Camera Link supplement toVision Systems Design and Image Processing Europe, May 2002).
Adept Technology Inc
San Jose, CA
San Diego, CA
Gray Cancer Institute
Northwood, Middlesex, UK
Hamamatsu Photonics UK
Welwyn Garden City, Herts, UK
Eindhoven, The Netherlands
Silver Spring, MD
Park Ridge, NJ
1394 Trade Association
Triptar Lens Co.
Ottawa, ON, Canada