Was that Slip and Fall for Real?

Video vault stores surveillance camera images for years

3 min read

Image: Viktor Koen

Lawyers may hate it, but insurance companies could grow to love it--a surveillance system, like the one devised by a New York City company, that won't forget what it sees. Images archived by the system could show, for example, what really happened on the occasion when that woman says she slipped on the sidewalk; or if that Ferrari already had a dented door when it came into the parking garage; or just what did occur at that construction site.

In most standard surveillance systems, images are recorded on VCRs near the cameras and stored for anywhere from a week to a month. That suffices to deter some people from sticking up convenience stores or breaking and entering. But the short storage periods are an opportunity for people staging accidents: they usually have to wait just 30 days until the images have been erased, and then file a lawsuit.

In stepped Fred Deutsch, the cofounder of VideoSave. As an owner of commercial real estate in New York City, he was aware of the problems arising from surveillance systems with impaired short-term memories and had an inkling of how to fix them. He knew that large numbers of surveillance video cameras were being installed in buildings and elsewhere. And he was being pestered by companies offering free installation of Internet access in his buildings so they could then sell it to his tenants. He also knew that the quality of the images was often poor and that videotapes could go missing at any time, depending on how carefully a building's staff looked after them. Deutsch got the idea of moving the storage out of the buildings and sending the images over the Internet to be stored more reliably elsewhere.

In the VideoSave system, images from the cameras are sent to a central "video vault," where they can be archived on hard drives for up to the three years of the legal statute of limitations. "We have an eyewitness with the best memory in the world," says Michael L. Hill, VideoSave's chief technical officer. With the vault connected to the Internet--the vault is actually a modest 2-meter-high equipment rack in a space on West 15th Street in Manhattan--clients can check their videos, date-stamped on receipt, with a PC or even a PDA and, soon, a 3G cellphone. The rack has 10 terabytes of storage now and can grow without limit.

A month of image data for one camera, accumulated at one frame per second, requires roughly 20gigabytes. For just one camera, then, this adds up to about 700 GB over three years. That would be too much to handle, notes Hill, even with the huge data-storage densities of today's consumer disk drives. Data compression is key. VideoSave, a privately held company, has been developing and tweaking its techniques for data compression, and for streaming video reliably to clients, for more than four years, at a cost of about US $3.5 million. For compression, the company relies on a "flavor" of the MPEG-4 system for compression of digital and high-definition TV imagery. Sending only changes from one frame to the next allows a frame with roughly 1.4 megabytes to be sent as less than a kilobyte, according to Hill. The software can also boost the camera's resolution and picture quality if anything out of the ordinary is detected. Frame rate can be stepped up to movie-like speed.

Programming is done remotely by a three-person staff whose chief, Mark Friedgen, is in Chicago. New software, like improved data-compression algorithms or other upgrades, can be downloaded to each camera. The system depends for reliability on a redundant array of inexpensive disks, a common architecture known by its acronym, RAID. Images are stored on more than one drive, so if one fails, the data are not lost. Cameras are also monitored and alerts sent if there's a malfunction.

In the field, Hill uses local independent technicians who install video surveillance gear. He supplies them with a box built around the Linux operating system that digitizes and compresses the images. A client's cable modem in the box or other Internet connection sends the images to VideoSave's host, which has battery and generator backup.

Business has been very good of late, says Hill. The number of customers has grown tenfold in the past year, and VideoSave now supports about 435 cameras. Fueling the boom is a law that went into effect last September in New York City. The law transfers liability for sidewalk accidents from the city to the owners of the abutting property. Now that property owners can be targets of those lawsuits, inquiries to VideoSave have jumped. The charge is $30 per camera for a month of archived images. Three years worth of archiving, which VideoSave is beginning to sell, is $60 per camera per month.

Should ordinary citizens worry about Big Brother watching them and storing what is seen as never before? "We're not doing things to make people who really have accidents any more vulnerable," Hill says, "but we can help reduce the amount we all pay for accidents that don't happen. Good records can only help people who really do have an accident."

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