Video surveillance technology offers plusses and minuses
Surveillance videos are getting sharper, and the systems that produce and manage them are growing smarter. Megapixel and high-definition cameras, thermal imaging, video analytics and other advanced technologies are giving safety and security professionals greater power to protect property and lives.
For surveillance systems that operate on wireless networks, these new technologies also pose new challenges. It takes a lot of bandwidth to move high-resolution digital video or thermal images. And, of course, it takes a lot more bandwidth to transmit from 200 cameras than it does from 20. As surveillance systems grow more capable, they’ll start appearing in more locations, putting new pressures on available wireless capacity.
It’s easy to understand why the technologies that bring bright, clear episodes of Dancing with the Stars into the home also are making inroads in the surveillance market. Video recorded with a megapixel or HD camera contains much more information than conventional video. So when you’re viewing a high-resolution video image and you drill in on an object, that image won’t degrade into a pixilated blur.
“You can zoom in 300 feet and see license plates,” said Ksenia Coffman, marketing manager at Firetide, a Los Gatos, Calif., firm that develops wireless mesh networks to support video systems.
Alan Salmon, special investigator/forensic video analyst at the Oklahoma State Bureau of Investigation and president of the Law Enforcement and Emergency Services Video Association International (LEVA), first got a look at high-resolution video in action three years ago. The megapixel camera he observed at LEVA’s annual meeting had recorded a wide-angle view of a parking lot. Viewers who zoomed in tight on vehicles were able to read individual license plates.
Try that with a conventional camera, and you won’t learn much, Salmon said. “A lot of times you can’t even tell what make of car it is, let alone the tag number,” he said.
While these high-resolution cameras have been around for several years, the technology is only starting to make an impact on the security market. One reason is cost.
“The big problem initially was that a megapixel camera was something like $10,000,” said Salmon, recalling the units he saw three years ago. Prices for conventional video cameras range from less than $100 to about $4,000, depending on their features, he said.
Another reason that high resolution technology has been slow to catch on for surveillance is the difficulty of deploying it for wireless applications. “It has not been widely adopted in public safety because of the capacity requirements,” Coffman said.
However, better compression is easing the way for high-volume surveillance systems on wireless networks, said Steve Surfaro, strategic channel manager and industry liaison at Axis Communications, a Swedish provider of network video systems with U.S. headquarters in Chelmsford, Mass.
“More efficient compression technologies, like H.264, allow for a much lower amount of bandwidth, often one-tenth of the bandwidth used by conventional Motion JPEG [M-JPEG] compression cameras,” he said.
Ratified in 2003, H.264 is used in consumer products such as Blu-Ray discs and Apple iPhones. It’s fairly new in the surveillance market, but it’s growing popular, Surfaro said. “H.264 is rapidly replacing all the existing compression technologies in the security industry.”
The less you need to compress a video stream, however, the more valuable that stream will be as evidence in a criminal case, said Grant Fredericks, a forensic video analyst based in Spokane, Wash. “Using a higher-end camera, but then attaching it to a low-end upload or compressing it is kind of pointless.” But higher-speed wireless networks allow law enforcement and the courts to take better advantage of the detailed images that high resolution cameras provide, he said.
Editor’s note: View “The impending explosion,” an expanded article on this topic, in the January edition of Urgent Communications.