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Computer-based intruder detection

You are having a romantic supper with your partner at your favourite restaurant when you receive an SMS on your cellphone: ‘Camera 4 – patio – motion detected.’ You know that for motion to be detected on this camera the trigger object has to be taller than 1 m, so the staffie is out of the question. You dial your home base from your cellphone and on connection browse to Camera 4 using the RemoteView facility on your cellphone.

And there you see it ... a person staring through the lounge window to observe what could be stolen, planning his moves before breaking in.

Whilst you watch the armed response suddenly appear on the scene - they also got a telephonic message that there was an intruder at your house, clearly stating the address and the area in question. They arrest the intruder and you finish your supper with coffee and cognac.

Is this a scene from '1984' by George Orwell with Big Brother playing its part? No, this is modern reality and happens every day. It is another example of how the conversion of modern technology (in this case motion detection driven by a computer-based digital surveillance system with GSM and SMS technology) can assist in intruder detection and asset protection.

How is this possible? The person has not entered your house yet and therefore could not be picked up by the sensors that are normally used to detect intrusion by traditional house alarm systems.

In this case a computer-based surveillance system was programmed using a 'mask' for motion detection, set up in such a manner as to ensure that only a human could trigger the pre-set condition. This means that it can 'see' through the window and detect any motion within its range. The system picks up motion by constantly comparing the current picture with the previous one, and if a certain percentage of the pixels (individual building blocks of a digital image) are different from the previous one, a set of predetermined events is triggered.

These could include:

* A voice ordering the person to leave the property immediately.

* Lights and other appliances being switched on.

* Telephone calls giving specific details to the armed response company.

* Alarms being triggered.

* SMS or a call to a cellular telephone.

Remote monitoring

Whilst this is happening, the owner may, from any remote location using a device such as a cellular phone, laptop or computer, view current events, play back historic data and obviously take appropriate action. The remote viewer can even save the images on the remote device if he is concerned that the system holding the historical images may be stolen before assistance may arrive.

Most security systems are used to prevent or detect intrusion. Benign detection may be where one needs to record an entry to a secured space. This could be as innocent as an authorised person entering an automated boom gate using an access card or by his vehicle licence plate being recognised by a system that records the images as well as time and date of entry for record purposes.

Malicious detection could be where a person breaches a security structure with bad intentions, as described above.

GIGO implies 'specify robustly'

The concept of 'garbage in garbage out' is more important when dealing with digital surveillance. The quality of the cameras used is of the utmost importance. As there is no degradation on digital images, evident on tape-based analog equipment, only cameras that fulfil the exact requirements should be installed. TV lines of 420 and up and the correct light intensity factors are of the utmost importance. Fortunately there are some sophisticated computer-based programs available that will guide the installer through the process of selecting the exact camera equipment suitable for any set of circumstances.

This was clearly demonstrated recently in a much-published case of an armed robbery at a department store where the suspects were captured after digital recorded images provided poster quality images of the intruders. This was achieved by using high quality cameras correctly configured and positioned to do the job at hand.

Structures such as fences, walls, electric fences, electric gates, booms, security check points, etc, are designed to prevent malicious entry. Once inside the secured area, beams, sensors and cameras are designed to detect and warn about an unlawful breach. These devices may trigger a variety of actions and each is designed for a specific purpose - the ultimate is to warn early enough as to prevent any danger to assets and lives, thus before the main structure is breached.

IT in the driving seat

The more processing power available to the device, the more advanced the reaction, as one needs processing power to drive the various devices described above. This creates a strong case for computer-based surveillance equipment as these can more easily access the standard communications devices that we have grown so accustomed to over the last decade - including the Internet, cellphones and SMS technology. It can also allow the user to dial in using the above to view from anywhere in the world what is actually happening and arrange appropriate action.

But intrusions may also include intrusion and violation of privacy. Who last opened the safe, because some important documents are nowhere to be found? What did the child minder do whilst we were at the movies last night? Where did that investigation docket go and who was the last to remove it from the central files? Who entered the hostel and was not supposed to and who allowed them entrance?

Security as a management tool

Modern surveillance technology has all the potential to be used as a management tool, allowing a supervisor to at any given time from his office computer observe all the various manufacturing processes that he is responsible for. Or the owner of a hairdressing salon using a system to ensure quality on work delivered. Or by a law enforcement agency to refute a claim of unlawful usage of force by a crime suspect. Or by a haulage company to ensure that cargo is safely delivered.

It may also be used to augment the services provided by a security company as an extension to guards and a trigger to armed response. In this case the camera will detect breaches of the perimeter as they take place and immediately inform the guard in the guardhouse whilst switching on alarms and spotlights and calling armed response.

Digital surveillance technology is just another building block to help us win the fight against unlawful intrusions. With computer speed and processing powers doubling roughly every nine months, who knows what the future holds?

Perhaps George Orwell was not all that far out in 1949 when he wrote his epic novel that gave the world Big Brother. And perhaps he will turn in his grave if he should know what reality television has done to his ideas.

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