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Caught on Camera

24 June 2008

With a recent estimate putting losses through fraud and theft in the retail sector at around £2bn per year, security in shopping centres is clearly a hot issue. Alistair Enser explains how improving security can be tackled efficiently and effect

CCTV IS THE BACKBONE of all modern retail security installations in retail environments. However, the police have found around 80 per cent of CCTV images currently captured to be of such poor quality that they can’t be used as evidence in court. Image quality is, therefore, an important issue.

The requirements for any CCTV installation can essentially be split into three sections – capturing the images, recording them and viewing them. Of course in this technological age we can talk about ‘hot topics’ like people tracking, people counting and analytics, but getting the basics correct initially is more important. The first decision to make is how many cameras to use, and where to put them. While it may initially seem tempting to go for blanket coverage with high-resolution cameras, this is an unnecessarily costly approach.

Siemens’ experience shows that a better solution is to capture images of sufficient quality to provide facial recognition at the point where people enter and leave the shopping centre or store. As they move between the entry and exit points, wider coverage is usually sufficient, as individuals can invariably be tracked by the clothes they are wearing, the bags they are carrying, etc. using strategically placed Pan Tilt Zoom Dome Cameras. This means that most of the ‘sales area’ can be protected by a relatively smaller number of cameras.

Further coverage will usually be recommended for special locations or ‘hot spots’ such as areas containing expensive and easily portable items, or adjacent to cash offices. In these locations it is a simple cost benefit equation relating to the value of the equipment versus the risk. This type of solution is more efficient on a cost-benefit ratio than providing facial-recognition quality coverage throughout the whole of the sales floor.

Capturing good images as people enter and leave the premises does present challenges, however, and failure to address these is one of the reasons that so much CCTV material is unusable as evidence. The key problem is that people entering are likely to be lit strongly from behind, with their faces in deep shadow. Ordinary cameras can’t cope with this high contrast range, and produce poor quality facial images. The solution is to choose cameras that have been specially designed to cope with contrast lighting, such as the recently introduced models that incorporate the new PIXIM technology.

Another important issue is deciding how many cameras to use. For a given area, the basic options are to use a few cameras with wideangle lenses, or to use more cameras, each of which has a narrower angle of view. The first option may seem attractive from a cost point of view, but problems start when it comes to examining image detail – enlarging a small area of a picture from a wide-angle camera in order to see more detail is hardly ever satisfactory. The better choice, therefore, is to opt for more cameras.

It’s worth noting that all cameras give their best results in good lighting conditions. Facilities managers may well, therefore, find that their wider skills are called upon to help optimise the operation of the CCTV system by reconfiguring lighting, and making changes to eliminate reflections of the sun or other light sources, which could interfere with correct camera operation.

For the recording of CCTV images, the only realistic option for new installations is digital recording which stores the image data on computer-style hard disks. Digital recording is not only capable of delivering excellent image quality, it is also much more secure, dependable and convenient than the use of old-fashioned VHS tapes. Digital video recorders (DVRs) are now very affordable, but there is one potential pitfall to look out for. All DVRs compress the image data before recording it on the hard disk, since this allows a given size of disk to offer a much larger storage capacity – in terms of hours – than could be achieved by recording the raw data.

However, compression results in some loss of image quality. With low levels of compression, this loss is almost undetectable but DVRs using very high levels of compression, and apparently offer an enormous amount of storage time at very low cost, give recorded images that are so compressed as to be blurry and lacking in detail. The final link in the CCTV chain is viewing the images, and Siemens experience is that this is the link most often neglected. Worn-out CRT monitors and first-generation flat panels with poor performance are often kept in service long after they’re capable of delivering good quality pictures. This false economy effectively negates the benefits of investments made elsewhere in the CCTV installation. FMs may, therefore, wish to check the performance of the monitors currently use on their sites, remembering that those used for security purposes have a hard life, often operating 24/7, and that replacements are surprisingly inexpensive!

CCTV is not the only component in the retail security mix. Since up to 50 per cent of losses are attributable to staff, there are clearly other measures that may be appropriate. Access control for stock rooms, cash rooms and other sensitive areas is one option, as are dedicated monitoring systems for point-of-sale terminals. These options give their best results when linked with the CCTV installation. The access control system, for example, can signal the CCTV to record more detailed images of an access point where an attempt is being made to use an invalid entry tag or card. Similarly, EPOS systems linked to the CCTV can help identify unusual transactions, such as refunds or voids. It is even possible to arrange for the EPOS data for the transaction to be superimposed on the recorded CCTV images of the event.

Many of the latest security systems make extensive use of network connections rather than conventional wiring, and the network protocols used are very likely to be the same as those used for the retail operation’s IT services. For FMs, this has two important implications:

● It may be possible to use a common network for security and IT, thereby reducing installation costs. This arrangement is not, however, necessarily appropriate in all situations, and expert advice should be sought before going down this path.

● Knowledge gained in implementing and maintaining the IT installation is equally applicable to the security system, which helps to make security system maintenance and fault finding much less burdensome tasks. There’s no doubt that, through the increased prices of goods, we all pay for theft and fraud in the retail sector. Fortunately, as we have seen, modern security systems, provided that they are correctly specified, installed and maintained, offer an effective way of controlling and identifying these losses.

● Alistair Enser is Sales and Marketing Director at Siemens Building Technologies Security Products

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