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Vision on guard

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Greg Blackman explores how the security market has moved on from analogue CCTV to more sophisticated imaging technologies

Security camera technology has advanced way beyond standard CCTV systems. In a world of heightened security, the need to monitor people is greater today than it has ever been. There is a thirst for more coverage, clearer images, and smarter technology all geared to capturing criminal behaviour and protecting people and property.

Gerrit Schreiber, product manager at Basler, estimates that the security camera market is currently worth $3bn, split between analogue and digital systems. Basler recently launched a family of IP cameras aimed at high-end security markets, such as airports, banks, and casinos. The cameras provide flexible compression options, while maintaining high resolution. ‘There is currently 10 per cent growth in the surveillance market and 40 per cent growth in IP cameras,’ suggests Schreiber.

The need for smarter systems is also growing. Viseum, a security camera manufacturer based in Kent, UK, produces an intelligently automated moving camera system. Development of Viseum’s system was not driven by advances in technology as such, but rather by issues with the existing surveillance systems and a need to provide solutions to those issues, explains Stuart Thompson, managing director of Viseum.

Thompson founded the company around the turn of the millennium to help reduce the cost of maintaining a system of CCTV cameras in local streets and neighbourhoods. At this time, while CCTV was relatively widespread, local councils only employed minimal numbers of operating staff to monitor cameras. ‘People think of CCTV as a Big Brother-type presence, but the reality is that often there isn’t anybody watching the cameras,’ Thompson says.

Following a feasibility study and the subsequent backing of Neighbourhood Watch, Thompson and his team set about engineering Viseum’s Virtual Operator Assistant (VOA), an intelligent moving camera that can be used as a standalone system or integrated into existing CCTV systems.

Instructions from pre-programmed surveillance profiles tell the system to lock onto and track an incident that is taking place, the motion of which can then control pan-tilt-zoom cameras integrated into the system to provide close-up court evidence.

A VOA camera automatically examines a scene, identifies objects in its field of view, tracks where they have been and intelligently predicts what they are about to do. The camera will automatically generate alerts depending on surveillance parameters and capture accurate video evidence according to Home Office guidelines.

Active Silicon, a digital imaging product manufacturer based in Uxbridge, UK, has recently been contracted to produce an embedded processor engine specifically for running the VOA. The embedded hardware is small and light enough to move around with relative ease, which, as Thompson explains, will benefit a lot of customers. ‘There is a big need for reduced size and weight of computer equipment local to the camera installation’ says Thompson, who goes on to explain that it will expand not only the intelligent moving camera (IMC) market but also the CCTV market in general.

Viseum are providing embedded systems to one of the largest police forces in the UK. Applications for this type of mobile system are numerous and allow surveillance and policing bodies to move their systems around depending on the areas requiring high levels of surveillance at a given time. Viseum is currently testing the embedded hardware produced by Active Silicon and expects the product to launch in May 2008.

Thermal imaging is also becoming more prevalent in high-end security applications. ‘Thermal imaging is coming down in price,’ says Mark Williamson, sales and marketing director at Firstsight Vision. ‘A thermal camera used to be 10 times the price of visible equipment, whereas now it’s just three to four times the cost.’ Williamson suggests that this is making thermal imaging more accessible to security firms.

Firstsight Vision, part of the Stemmer Imaging Group, supplies a range of thermal imaging equipment from Opgal Optronic Industries. ‘Most CCTV in shops and low-end security applications is used for identification purposes,’ explains Williamson. ‘Thermal imaging is more suited to detection of people over large areas.’

Thermal imaging is utilised in high-end security applications, such as prisons, airports, and border control. The cameras can detect and identify people over a larger area than would be possible using visible imaging, so far fewer thermal cameras are needed. For this reason, it is often more cost effective to use fewer, more expensive thermal cameras rather than many CCTV cameras.

Thermal imaging works effectively 24 hours a day, irrespective of weather conditions, and is often used to alert security personnel to an intruder’s presence enabling pan-tilt-zoom visible cameras to provide further coverage and identify the suspect.

‘Image fusion technology’ provides the best of both worlds. This technology employs computer software to match up and superimpose visible with thermal images, creating a composite picture that contains far more useful surveillance information than either of the individual images.

Andrew Rimmer, business development director at Northampton-based thermal imaging company Irisys, expresses similar sentiments in regards to the cost of thermal imaging cameras. ‘What we’re now seeing in the market is the price [of thermal cameras] coming down,’ says Rimmer.

Rimmer goes on to explain that whereas in the past thermal imaging cameras have been used mainly for military applications due to their high cost, now cameras are retailing at fewer than £3,500 for a handheld system. Irisys provides handheld cameras to the police for applications such as checking for trespassers on railway sidings at night or for identifying cannabis factories.

Surveillance equipment – and the intelligent imaging technology behind it – is becoming ever more sophisticated.

A further advantage of thermal imaging over visible or infrared systems is the cost of lighting. Running spotlights to enable the cameras to operate 24 hours a day is not only costly in monetary terms, but also in environmental terms.

Rimmer suggests that thermal imaging cameras, while initially more expensive, would be cheaper to run and a ‘greener’ alternative to visible and infrared systems. In addition to its high-resolution thermal imaging cameras, Irisys also produces lowresolution thermal imaging devices for the express purpose of counting people. The technology is utilised mainly within the retail industry to obtain accurate counts of customers visiting their premises. More than 50,000 people-counting units are installed in stores worldwide, including big name brands such as Marks & Spencer and Virgin. These devices, however, are also becoming increasingly popular as an effective addition to many security systems.

Companies utilising secure access points, in which staff are required to present an electronic pass to a system to gain access to the building, can suffer a security breach simply by intruders following a member of staff through supposedly secure doors, a practice known as ‘tailgating’.

Irisys’ tailgate detector uses a 16 x 16 pixel pyroelectric array along with advanced tracking and detection algorithms, to produce a thermal image with sufficient spatial information to detect and track people.

The tailgate detectors are placed at access points and are integrated into the building’s access system. A count line is programmed into the detector and anyone crossing the line will register on the system. A comparison is then made between the number of valid cardholders swiping into the system and the number of people detected entering the building. Discrepancies between these two figures will trigger an alarm and implement other security measures, flagging up CCTV footage to security personnel, for example. ‘All of the processing is carried out in the head itself,’ explains Rimmer, going on to point out that the low resolution and small amounts of data being dealt with allow a low-cost, highly accurate, easy-to-install and integrated detection system to be set up.

The detectors are highly accurate, explains Rimmer, as they are positioned looking straight down. This allows two people to be counted even when side-by-side.

Tailgate detectors are suitable for medium- to high-end security applications. For instance, Irisys has installed units for pharmaceutical companies dealing with hazardous substances and requiring a high level of security.

Irisys detectors not only alert to potential unauthorised access but also provide a reliable headcount of the number of people exiting a building during an emergency evacuation. This is especially important for high-rise buildings, such as those at Canary Wharf, for which Irisys provides people-counting devices, where there are no muster points for people to congregate during an evacuation. The number of people exiting the building can be accurately monitored and will provide vital information to emergency service personnel of anyone left inside the building.

Thermal imaging – which is coming down in price all the time – can be used 24 hours a day, making it ideal for use in security applications. Image courtesy of Firstsight Vision.

Whilst the latest technology in smart cameras and thermal imaging is becoming more widely used within the security market, there is still a large body of analogue CCTV devices in operation.

Frame grabbers allow companies to retain their analogue cameras and other existing equipment inherent in their security setup. Andrew Buglass, product manager at Active Silicon’s UK headquarters in Uxbridge, believes that most companies find their current analogue setup sufficiently effective and introducing frame grabbers removes the unnecessary expenditure of upgrading cameras, cabling and so on. ‘The image quality may not be as good as some of the other options around, but for many companies it is adequate for their needs,’ explains Buglass.

Buglass feels that analogue cameras aren’t going away. ‘Customers want to stick with their current systems, at least for the time being,’ he says. ‘I think, in the future, one will see a move toward more intelligent systems.’ Smarter systems, such as those produced by Viseum, reduces the cost of an array of screens, replacing them with just one or two monitors, with the system programmed to alert the operator to any suspicious behaviour. ‘That’s the holy grail for security systems – one that runs itself.’

X-RAY MOVES ON

Bomb detection equipment is vital to maintain safety and security in highthroughput areas such as ports and railway stations. 3DX-Ray, a producer of X-ray imaging equipment based in Leicestershire, UK, supplies TPXi portable X-ray bomb and threat detection systems for military, police, and custom inspection applications.

The British Transport Police utilises the TPXi system in all major railway and underground stations within the city of London. ‘The X-ray systems are used quite heavily – two or three times a day on some occasions,’ says Nick Fox, managing director of 3DX-Ray.

See-through... X-ray vision is increasingly important in baggage searches.

Suspicious packages were, in the past, destroyed using a controlled explosion. The X-ray systems used then were bulky devices with low resolution. ‘Now, however, there’s a requirement to know what is inside a bag,’ explains Fox.

Destroying a device containing radioactive or biologically hazardous material could have disastrous consequences. ‘That is what the terrorist wants – for the device to be detonated.’ Many of the features of the portable system are techniques developed from the baggage inspection market. ‘The X-ray device is a line scan imaging system,’ says Fox. Instead of bags moving past an X-ray camera along a conveyor belt, the bag remains stationary and the X-rays scan across the bag.

Objects can now be resolved to 50- 60μm and advances have been made in the size of the imaging area. Traditional systems that can only analyse a small area require bomb disposal experts to return to the suspicious item to change the position of the detector. ‘Developers of this equipment are always looking for larger imaging areas,’ says Fox. 3DXRay’s TPXi system has a detector area measuring 500 x 400mm.

The detector is also thin (5cm deep), a distinct advantage over older, bulkier detectors. The thin design allows bags placed against a wall to be checked, something that wasn’t possible using thicker detectors.

Dual-energy X-ray analysis allows the system to distinguish between organic and inorganic objects. These are colourcoded depending on the detected material’s atomic number, so that organic substances, such as semtex, will appear bright orange, while inorganic objects, such as knives, will be shown in blue/black. This allows operators to easily identify potentially hazardous material.

Operators can also view the image in 3D. ‘Usually, X-ray imaging is one of the few imaging techniques to produce a truly 2D image,’ explains Fox. 3D X-ray technology captures two different views of the same package, providing depth to an image and ensuring that the operator can rapidly understand the relationship between objects within the package – this is not possible without 3D views.

‘A lot of the image analysis is automated,’ explains Fox. The contrast is enhanced using an algorithm called ‘DeepFocus’, so that a clear image is achieved displaying the maximum amount of detail without needing to process the image further. ‘We aim to provide “best image, first time” results,’ says Fox, to ensure that the image captured contains all the necessary information without needing to improve the image quality.

Fibre optic links are being developed to allow the image to be viewed over a long distance. ‘Most of the equipment supplied to the British Transport Police has a wireless connection, which is fine in London, but could be a problem in rural areas where devices could be detonated wirelessly,’ explains Fox.

VISION CROSSES BORDERS

Borders security is essential to monitor traffic of people between countries. Avalon Biometrics’ Secure Border Management System (SBMS) is used by immigration authorities to control entry and exit to and from a country. SBMS supports the new electronic passports and visas in addition to the automated verification of printed security documents. It has a variety of features: biometric analysis, face recognition, fingerprint comparison, control list checks, and intelligent character recognition (ICR) of entry/exit cards.

At the end of 2005 Avalon Biometrics was awarded the contract to supply the new border control system for the Spanish police; the system supplied incorporates both biometrics and document verification. The document verification component of SBMS, called VeriDoc, provides verification of travel documents, checking that it has not been tampered with. The security features are checked against the templates stored in the database and all verifications are performed automatically by analysing images and comparing security patterns and features under various light sources.

Utilising Matrox Imaging’s Library (MIL), a programming library for image processing, Avalon is able to extract a large amount of statistical information from the document images in various light sources. Using its own matching system in conjunction with MIL, Avalon increased automatic document identification accuracy to more than 99 per cent and document verification to 97 per cent.

‘The more security checks that are defined for passenger processing, including document, biometrics and control list verifications, the greater the time spent at immigration control, explains Alejandro Gomez de Cuenca, chief technical officer at Avalon Biometrics. ‘There is always a trade-off between the number of checks and the amount of time taken to process a passenger. Compared to security measures at US border  controls, the SBMS system processes passengers rapidly, taking fewer than 45 seconds per person.’

The document verification module of SBMS complies with international standards for the format and layout of passports and travel documents set out by the International Civil Aviation Organization (ICAO), a UN agency dealing with the safety, security, and sustainability of civil aviation. ‘The standards are only recommendations, but are becoming increasingly adhered to,’ says de Cuenca.

However, every country will have specific ways of enforcing border control. ‘We always have to customise the system for different countries based on customer requirements,’ explains de Cuenca. The basic architecture for the system remains, however, the same.

The ICAO also makes recommendations on the implementation of biometrics within secured documents. These checks, in which the live captured data from passengers is compared against information stored in the documents, are fully supported by SBMS. ‘In the future, more and more passports will contain biometric information. All EU countries are now issuing e-passports capable of holding biometric data,’ says de Cuenca.

To date, Avalon Biometrics has implemented projects in Spain, South Africa, Brazil, Nigeria and Liberia.

The SBMS system in action.