[Engineering Feature]
Would You Believe...? Machine Vision Gets Smarter
More powerful cameras and greater video-analysis capabilities push intelligent video beyond traditional industrial uses to surveillance, consumer, automotive, and other applications.
Roger Allan
ED Online ID #18803
May 8, 2008
Copyright © 2006 Penton Media, Inc., All rights reserved. Printing of this document is for personal use only.
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Intelligent video’s expanding presence in all sorts of applications
is driven by several factors: the shift from analog to
digital sensing; improved wired and wireless networking;
and more sophisticated software. The latest systems push
beyond basic image sensing and capture capabilities to image
analysis, thanks to powerful video-processing hardware and
intelligent video software.
Today’s intelligent cameras are replacing yesterday’s PCbased
systems in terms of functionality. These ever-shrinking cameras
feature faster and higher-bandwidth connections between their outputs
and other circuits, with some functions on the sensing chip and many
more functions within the box or housing itself. Previously, such functions
required an external PC platform or a host computer for processing.
From the business side, intelligent video has become a matter of
practicality. In manufacturing, it’s virtually impossible to examine products coming off a high-speed production line for quality and
defects without using intelligent video systems. In surveillance,
security personnel viewing a monitor at an airport or other public
facility face the dual challenge of spotting the bad guys while
fighting off boredom.
Intelligent video-surveillance systems aren’t just more vigilant,
they’re also more accurate. With their greater intelligence, they can
discern nuances in observed individuals and make the necessary
critical analyses and judgments that are difficult if not impossible for
a human operator.
In addition to getting more intelligent by using on-chip or
in-the-camera-box hardware and software, video cameras can
support downloadable modules produced by third-party vendors.
Some companies offer totally integrated camera solutions, while
others allow for more flexibility. Flexibility in this case means that
the user can fine-tune the camera system to observe and track a
specific type of object or objects for specific features. The trend is
to gather a small amount of data at high speed from the camera
sensor for further analysis down the line, leading to a more intelligent
analysis of what is being viewed.
VIDEO INTELLIGENCE IS BIG BUSINESS
Major cities in the U.S. and other countries now use sophisticated
video-surveillance technology to improve their security infrastructure.
Chicago, Ill., for instance, has partnered with IBM to
implement a smart video-surveillance network that’s been dubbed
the most advanced of its kind in the U.S. It can alert officials whenever
it detects a specific vehicle’s license-plate number, observes a
vehicle circling a specific location, or spies an unattended object.
“Video surveillance is the fastest-growing market for digital
video chip providers,” says Chris Day, president and CEO of
Mobilygen. According to the China Security Market Report
issued by the Security Industry Association, China’s video security
and protection market (including fire and safety monitoring,
security surveillance, and access control) is projected to jump from
$6.3 billion in 2005 to $18 billion by 2010.
TWO APPROACHES
Broadly speaking, there are two types of intelligent camera systems:
smart or IP cameras and embedded systems. Smart cameras
integrate the camera sensor and the processing circuitry.
In embedded systems, the video sensing is in one location. It’s
connected either wirelessly or by wire to an embedded system
elsewhere that consists of a frame-grabber board and a processor
external to the camera sensor.
These differences are narrowing, though. Some smart cameras
have so much intelligence, either on the sensing chip or within
the same case holding the chip, that many of their manufacturers
consider them embedded systems. However, the application usually
dictates the type of camera system needed.
Smart cameras are more useful in space-challenged applications,
but typically they don’t have as much processing power as
the embedded approach. Although they’re generally less expensive
than embedded camera systems, that cost advantage can quickly
evaporate when using multiple cameras.
An embedded approach will offer greater programming flexibility
and becomes a very desirable option for applications in which
multiple cameras are used to view many scenes. Moreover, it can
support a wide range of cameras from different manufacturers ,
which is another space-saving feature because one embedded unit
can service multiple cameras. On top of that, it provides more freedom
when choosing a camera signal’s interface.
Leutron Vision’s LVmPC micro PC uses the embedded approach
to save space in embedded vision applications. It combines innovative
notebook and frame-grabber technologies in a small 91- by
92- by 182-mm footprint. Designed for popular operating systems
like Windows, Linux, and VxWorks, it uses Intel’s ultra-low-power
Pentium III and Celeron processors.
Another space-saver is the CCD-based (charge-coupled device)
In-Sight Micro smart camera from Cognex, which measures just
30 by 30 by 60 mm (Fig. 1). It’s designed for mounting in tight
spaces on robots, production lines, and machinery. A flexible
mounting capability with a non-linear calibration tool allows for
mounting at angles up to 45° for hard-to-reach applications.
Most machine-vision cameras use CMOS sensors in applications
where low cost is important and performance isn’t demanding.
CCD imagers, though, dominate applications that require
high performance (see “Choosing An Image Sensor: It’s All About The
Application” at www.electronicdesign.com, Drill Deeper 18801).
Roughly half of all image sensors are analog, with the other half
being digital. Both types have driven the trend toward smaller
machine-vision cameras.
Continued on page 2
But CMOS-based cameras aren’t far behind in performance.
The CMOS A400 area scan series from Basler Vision Technologies AG targets industrial users who
require high resolution (up to
4 Mpixels) coupled with high
speed (96 frames/s). Its three
shading correction choices contribute
to image quality.
A multiple sequencer built
into each camera lets users
change the automated-optical
inspection setting from frame
to frame with no time delay. A
standard Camera Link interface
simplifies system integration and provides increased flexibility
when changing cameras or frame grabbers. Like many other
manufacturers, Basler also offers CCD-based cameras.
The latest camera-sensor advances often involve the optics
rather the type of sensor used. For example, Tessera Technologies
Inc. is making its OptiML Zoom available for licensing.
This capability combines a unique lens design with specialized
algorithms to replace traditional mechanical zoom capabilities,
enabling 3X zoom capabilities in a compact camera module.
OptiML Zoom permits camera-phone module makers to integrate
vintage zoom functionality at a lower cost than traditional
mechanical approaches, without the need for any moving parts. In
addition, it reduces the overall size of the camera module.
Designers looking for high-quality camera images with high
resolution may want to consider the hardware-acceleration Fast-
Track IP from FotoNation. It improves face-tracking quality and
performance up to 400% in digital cameras and camera phones.
This is achieved by integrating location and exposure information
of human faces with the camera’s exposure feedback system.
SMART ANALYTICS
Today’s smart cameras feature built-in “video analytics,” a term
that emerged during the 1990s to describe computer vision smarts
for security and surveillance systems. Powerful DSPs now can
execute more demanding software applications for video systems.
They constitute the processing cores of intelligent video codecs
like Siemens’ Sistore CX codecs. Acting with a host computer or
a PC, they allow general administration, storage, and networking
tasks of video system information.
One example of a smart
camera, the CCD-based Li045
from Lumenera Corp., includes
a Texas Instruments DaVincibased
processor. It uses the
Pixim Orca chip set, an ultrawideband
(120-dB) sensor that
overcomes washed-out images
in challenging lighting environments.
It delivers high-caliber
color rendition and image quality
under various lighting conditions,
as well as selectable MJPEG and H.264 compression.
The company also recently released the Lm085 mini. This
small form-factor (44 by 44 by 56 mm) CMOS camera offers a
100-dB dynamic range designed for challenging industrial environments
with uncontrolled lighting conditions and tight space
constraints (Fig. 2).
“Texas Instruments pioneered many algorithms for video analytics
during the last two decades,” says Bruce Flinchbaugh, a Texas
Instruments Fellow and director of its video and image processing
laboratory. He points out that many of today’s smart cameras are
built on TI’s DaVinci platform with a multitude of processors and
that “the TI TMS320DM642 DSP has been instrumental in reducing
the costs of video analytics applications, especially for digital
video recorders.”
The TMS320DM642 is based on the second-generation highperformance,
advanced VelociTI very long-instruction-word
(VLIW) architecture developed by TI. Performance measures up
to 5760 MIPS at a 720-MHz clock rate.
TI’s DM355IPNC-MT-5 high-definition, IP network camera
reference design is based on the DaVinci TMS320DM355
digital media processor and Aptina’s 5-Mpixel high-definition
security image sensor. Aimed at IP surveillance networks, it
provides flexibility for an easy upgrade path to IP video at analog
video-camera prices.
Texas Instruments’ TMS320DM6446 DaVinci platform and
Pixim’s sensor are behind Nuvation’s ultra-compact IP Power over
Ethernet (PoE) camera (Fig. 3). More recently, Nuvation introduced
four video reference designs for the DaVinci platform to
accelerate time-to-market.
Apollo Imaging Technologies
also uses TI’s digital media
processors in cameras aimed at
OEMs for applications in fire,
smoke and intrusion detection,
true-color night vision, highspeed
digital camera/event
analysis, and unmanned aerialvehicle
(UAV) video links. The
company offers a low-cost imaging
video-analytics development
platform.
The Edge products from Cernium
Corp. combine the company’s
patented P-Core analytics
technology with the portability
of a DSP platform like the TI
DM642 and DaVinci processors. This enables higher performance
than DSP-based products alone can offer, because analytics
is possible for a complete suite of behaviors on multiple inputs.
Continued on page 3
Many other processors on the market target video systems,
including the PowerPC; Intel’s Pentium III, Celeron, and X86
processors; and AMD’s Geode SC2200. Ann Arbor Systems
uses Analog Devices’ Blackfin ADSP-BF533 DSP to power its
AXT100 thermal infrared-imaging camera (Fig. 4).
Startup company Stretch Inc. offers wrapped designs and software
around its S6000a configurable processor for building lowcost
networked surveillance cameras and digital video recorders.
The company says its approach can deliver 30 frames/s for an
H.264 codec video stream at D1 standard resolution—at a cost of
as little as $6.25 for the processor.
Some companies like Apollo Imaging Technologies try to cram
as much video circuitry into cameras designed for OEMs that
specialize in developing video analytics. These OEMs also have
IP primarily in the image-processing arena, as opposed to highperformance
image-processing hardware development.
Functioning as development platforms, such products typically
feature enough capability to replace a conventional camera, PC,
frame grabber, and associated cable, power supplies, and other
components, all within the space of an industrial camera.
THE RIGHT DEVELOPMENT TOOLS
Development tools as well as the software and its algorithms are
key to cost-effectively developing intelligent video systems while
meeting time-to-market. To that end, National Instruments’ NI
Vision represents one of the more powerful and comprehensive
development and software platforms.
NI Vision’s hardware ranges from plug-in devices for PCI and
PXI systems to image processing on the sensor itself with NI’s
Smart Camera (Fig. 5). Options include image-acquisition software
to acquire images from thousands of cameras, a top-notch
image-processing library, and a configurable interface for industrial
machine-vision applications.
“It is important that a smart camera’s software platform be
extremely open and flexible to handle a variety of different requirements.
That’s the philosophy behind NI’s approach,” says Matt
Slaughter, product marketing
manager for NI Vision. “A lot of
people are trying to make it easier
to use out-of-the-box vision
systems without having to invest
a lot of money.”
When Sylvania Lighting
needed to integrate machine
vision and motion hardware and
software to produce improved
metal-halide lamps, it turned to
NI’s products. It chose a Windows-
based PC along with NI’s
PCI7831R reconfigurable I/O
board with an on-board FPGA,
an NI PCI-7356 motion board,
and an NI PCI-8252 IEEE 1394
camera interface board. The development software included NI
LabVIEW, the NI Vision Assistant, and an NI LabVIEW FPGA.
Many popular operating systems are being used to develop
intelligent video systems. These include Windows CE, XP, .NET
and XP embedded (XPe), and VxWorks. Linux with its opensource
platform is another popular software choice.
INTERFACES
Several standard analog and digital interfaces are available, including
FireWire (IEEE 1394), GbE (Gigabit Ethernet), USB, and
Camera Link. Each accommodates different data-transmission
rates, cable lengths and types, interface boards, the number of
cameras supported, and plug-and-play capability (see “Different
Interfaces For Camera Signals,” Drill Deeper 18804).
GbE is a popular interface standard for high-performance,
machine-vision industrial cameras like the Dalsa Corp. Genie
Color series (Fig. 6). The Automated Imaging Association is overseeing
the standard’s ongoing development and administration. It
features a data-transfer rate up to 1000 Mbits/s for distances up to
150 m, exceeding those of FireWire, USB, and Camera Link.
Increased camera intelligence and greater functionality have
highlighted the need for a comprehensive application programming
interface (API). As a result, the European Machine Vision
Association (EMVA) has developed the GenICam standard,
which encompasses cameras, the types of transport layer interfaces,
and software libraries, regardless of type or brand name (Fig. 7).
The standard consists of GenApi for configuring a camera,
SFNC for a standard naming convention for common camera features,
and GenTL, a transport layer interface for frame grabbers.
GenApi is a current part of the official standard, release 1.1.0. The
GenTL specification is expected to be completed soon.
Wireless video connectivity has also improved. Developed to
increase both the range and transfer rate of wireless video signals,
the 802.11n protocol allows the use of advanced encryption techniques.
It features operating frequencies of 2.4 and 5 GHz and a
maximum data-transmission rate of 248 Mbits/s.
For more on the future of intelligent video, see “What’s Coming In
Machine Vision” at www.electronicdesign.com, Drill Deeper 18802.
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