Bullies On Video

• By Michael Fickes
• 08/01/10

A Midwestern school district discovered by accident the power of an emerging video surveillance technology.

The district had recently upgraded the video surveillance system monitoring the playground of one of its elementary schools. The basic idea was to keep an eye on the kids, make sure they didn’t wander off or get lured away by a stranger.

But the new system soon faced a more difficult test. Three months after the installation had been completed, a parent reported that a bully had been tormenting her son during recess.

The new system could store six months of images. At the time of the bullying report, the storage drives held video for every recess that had taken place for the past three months.

Just as important, the new system made it possible to search the video quickly and efficiently. An intelligent component of the system called video analytics attached a tag to the image of the boy enabled school administrators to follow him at recess. The video showed a number of incidents in which the boy had been bullied.

The high-resolution images could be enlarged to show close-ups of the faces of the victim and the bully, leaving no doubt as to the bully’s identity.

The bully was disciplined and enrolled in a counseling program.

And the school district has ordered similar video systems for its other elementary school playgrounds.

How New Video Technology Did It
The school’s old video system could not have stored, found, tracked and enlarged the series of bullying incidents.

“A typical analog or digital video recorder probably wouldn’t store enough video to develop evidence in a case like this,” says Robert Harper, president and owner of ACS Electronic Systems in Lenexa, Kan., near Kansas City, Mo., the security technology integrator that installed the system. “Even if it could store the video, it would have taken a long time to find the key scenes, and then it wouldn’t have been able to zoom in for close-ups that confirmed the identification.”

The new system featured high-resolution three-megapixel cameras; a playback system that could zoom in to close-ups of actions, faces, license plate numbers and other details within the scene; and a storage system capable of storing enormous amounts of data economically.

The older analog camera system being replaced actually could have zoomed in, but detail captured by the cameras could not support a close-up view. The scene would have disintegrated into the individual pixels composing the image — a phenomenon called pixilation, which you may have noticed affecting cable and satellite television systems during severe thunderstorms.

The difference is that older cameras generate 80,000 to 360,000 pixels of information. By contrast the new three-megapixel cameras each capture three million pixels of data in each video frame, enough to support close-up views of the video.

Months of Video Storage
The new system also employed a new video storage scheme designed to store all those pixels economically.

Early digital recording systems were designed to store about 30 days of video. Storing more requires buying more disk drives — so many more that it can quickly become expensive.

Add to that the dramatically larger video footprint of three-megapixel cameras and conventional storage technology can become prohibitively expensive.

The systems being installed by ACS employ a new storage format called H.264, which can store more video information than older storage formats. “The cameras capture the video at the highest quality and highest frame rate and transpose it the H.264 for storage,” says Scott Carter, founder and vice president of business development for Mt. Laurel, N.J.-based TimeSight Systems, Inc., which supplies ACS with digital video recorders.

One TimeSight customer replaced 14 working digital video recorders with three H.264 servers, while growing from 30 days of video storage to 90 days. H.264 wasn’t responsible for the entire savings. TimeSight also manages the lifecycle of the video with a software application that increases compression and reduces frame rates as the video ages. Both techniques save storage space.

While compression and frame rate reduction degrade the quality of the video, remember that the video started out as high resolution. Even when compressed, high-resolution video retains quite a bit of detail — enough to identify the elementary school bully after three months of increasing compression, for instance.

According to Carter, the new storage technologies make it possible to store a year’s worth of high-resolution video for the same cost of storing 30 days of low-resolution video using conventional storage techniques.

Video Analytics
TimeSight systems also contain video analytics, a software capability that can monitor video and alarm on certain behavior. It can also track events and people over time in months and months of stored video.

“During recording, analytics can be set to alarm on important behaviors and to ignore unimportant behavior,” says Harper. “For instance, the playgrounds at the elementary schools where we are installing systems have a number of trees. The motion of the leaves in the trees blowing in the wind will activate the cameras and take up a lot of storage space. We can set the video analytic systems to ignore that motion. That saves storage space.”

Recording detailed high-resolution images, storing large volumes of video for a year or more at economical costs and quickly searching out evidentiary video clips from mounds of stored images are combining to give video surveillance technology entirely new capabilities for schools. Finding and helping to stop bullies fast is one of the first of these new capabilities to emerge.