The Truth About Surveillance Systems : Reality vs. TV

We've all seen the TV crime shows where the forensic technician opens the grainy surveillance, then zooms in on a tiny face, license plate or scrap of paper, hits the enhance button and, magically, the image becomes sharp and clear (accompanied by appropriate background music).

We know that's TV, but the question is, what can be done realistically to enhance surveillance video and what are limitations?

I'm going to address the most common surveillance systems. The ones used at convenience stores, small businesses, home systems, supermarkets, etc. This does not apply to the high-end systems used in casinos and those installed at sensitive federal facilities.

Here is what legal investigators need to know:

The typical commercial surveillance cameras (even most HD models) have a range of around 21 feet from a subject from which they deliver usable facial recognition data.

When you walk into a super market or pharmacy and look for cameras. They are on the ceiling some 20 feet above the floor. They take pictures of the tops of peoples' heads. We work on two or three surveillance videos a week. Inevitably, in a hold-up scenario, the suspects are wearing a billed cap which obscures the face. They know the cameras are above them which is why they wear ball caps.

Putting cameras in ceilings is easiest, but they would be much more effective installed at eye level. Proprietors might have a few ceiling cameras installed and feel safer, but other than possible deterrence, these cameras are probably useful only in slip-and fall cases, not anything that demands facial recognition.

Since the cameras that are closest to the action are looking down at the cap-wearing suspect, we can't usually get a good image to clarify. In these cases we have to rely on the images captured by the cameras that are farther, and possibly caught a better angle of a suspect entering or leaving a scene. But the farther away the camera, the less chance there is of obtaining a useable image. Can that video be "enhanced"?

Video enhancement depends on a number of factors.

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