It might be a sad indictment on today’s society, but surveillance cameras are an increasingly common sight on city streets around the world. Most of these systems employ a fish-eye lens to capture a wide field of view, but such lenses distort the image and can only provide limited resolution. A new video surveillance system currently being developed by the Department of Homeland Security’s Science and Technology Directorate (S&T) overcomes these shortfalls to provide perfectly detailed, edge-to-edge images that could prove to be of great assistance to law enforcement.
The Imaging System for Immersive Surveillance (ISIS) makes use of new video camera and image-stitching technology and can be bolted to a ceiling, mounted on a roof, or fastened to a truck-mounted telescoping mast. The unit makes use of a series of individual cameras to create video that is stitched together into a single, 360-degree, live view like a high-resolution video quilt. This means that, unlike traditional surveillance cameras, the device allows law enforcement to zoom in on a specific point of interest without losing visual contact with the rest of the scene.
"Coverage this sweeping, with detail this fine, requires a very high pixel count," says program manager Dr. John Fortune, of S&T's Infrastructure and Geophysical Division, "ISIS has a resolution capability of 100 megapixels." That's as detailed as 50 full-HDTV movies playing at once, with and means it can zoom in closer and closer without losing clarity.
Stitching not cutting-edgeThe stitching together of several images isn't exactly cutting-edge magic. For years, photographers have used low-cost stitching software and robotic camera mounts, such as those from GigaPan Systems, to create breathtaking high-res images. But those are still images, created days or weeks after a scene was shot. ISIS is quilting video—in real time. And, a unique interface allows maintenance of the full field of view, while a focal point of choice can be magnified.
The system is also capable of other tricks thanks to a suite of software applications called video analytics – many of which are commercially available. One app can define a sacrosanct "exclusion zone," for which ISIS provides an alert the moment it's breached. Another lets the operator pick a target – a person, a package, or a pickup truck – and the detailed viewing window will tag it and follow it, automatically panning and tilting as needed. The developers say that video analytics at high resolution across a 360-degree field of view, coupled with the ability to follow objects against a cluttered background, would provide enhanced situational awareness as an incident unfolds.
In the event that a terrorist attack occurs, forensic investigators can pore over the most recent video, using pan, zoom, and tilt controls to reconstruct who did what and when. Because these controls are virtual, different regions of a crime scene can feasibly be studied by separate investigative teams simultaneously.
Off the shelf componentsMany of the ISIS capabilities were adapted from technology previously developed by MIT's Lincoln Laboratory for military applications, which built the current system with the help of technology experts from the Department of Energy's Pacific Northwest National Laboratory using commercial off-the-shelf cameras, computers, image processing boards and software.
ISIS creators already have their eyes on a new and improved second generation model, complete with custom sensors and video boards, longer range cameras, higher resolution, a more efficient video format, and a discreet, chandelier-like frame – no bigger than a basketball. Eventually, the Department plans to develop a version of ISIS that will use infrared cameras to detect events that occur at night.
S&T formed a partnership with the Massachusetts Port Authority (Massport), and in December 2009, began an ISIS pilot at Logan International Airport, allowing potential Homeland Security end users the opportunity to evaluate the technology. If successful, the current testing at Logan could pave the way for the eventual deployment of ISIS to protect other critical venues.