Science Fair Project Encyclopedia
Closed-circuit television (CCTV), as a collection surveillance cameras doing video surveillance, is the use of television cameras for surveillance. It differs from broadcast television in that all components are directly linked via cables or other direct means. CCTV is used in banks, casinos, shopping centres, streets, airports etc. (the eye in the sky). The use of CCTVs in public places has increased, causing debate over security vs. privacy.
Closed Circuit TV (CCTV) - where the picture is viewed or recorded, but not broadcast - was initially developed as a means of security for banks. Today it has developed to the point where it is simple and inexpensive enough to be used in home security systems, and for everyday surveillance.
Use of CCTV
The use of CCTV surveillance cameras monitoring public spaces has become common in the 21st century.
In the United Kingdom, several trial programs in the early 1990s were deemed successful, and have led to a massive increase in the number of CCTV systems installed, with systems covering most town and city centres. Claims that they reduce or deter crime have not been clearly borne out by studies, though the government claim that when properly used they do result in deterrence, rather than displacement. One clear effect that has been is a reduction of car crime when used in car parks. Despite this, the British public remain so far generally supportive of CCTV, and local authorities continue to press ahead with more cameras.
The most measurable effect of CCTV is not on crime prevention, but on detection and prosecution. Several notable murder cases have been solved with the use of CCTV evidence, notably the Jamie Bulger case, and catching David Copeland, the Soho nail bomber. The use of CCTV to track the movements of missing children is now routine.
Opponents of CCTV point out the loss of privacy of the people under surveillance, and the negative impact of surveillance on civil liberties. Furthermore, they argue that CCTV displaces crime, rather than reducing it. The recent growth of CCTV in housing areas also raises serious issues about the extent to which CCTV is being used as a social control measure rather than simply a deterrent to crime.
The first CCTV cameras used in public spaces were crude, conspicuous, low definition black and white systems without the ability to zoom or pan. Modern CCTV cameras use small high definition colour cameras that can not only focus to resolve minute detail, but by linking the control of the cameras to a computer, objects can be tracked semi-automatically. For example, they can track movement across a scene where there should be no movement, or they can lock onto a single object in a busy environment and follow it. Being computerised, this tracking process can also work between cameras.
Currently, in some areas of the UK such as London, CCTV is being combined with computer imaging systems to track car number-plates. This is being developed in part as a security measure, or as a means of locating cars reported stolen. The London Congestion charge also relies on computer identification of car number plates to generate billing information. Critics point out that this produces a potential source of information on the location of persons or groups. There is no technological limitation preventing a network of such cameras from tracking the movement of individuals.
CCTV critics see the most disturbing extension to this technology is the recognition of faces from high-definition CCTV images. With this technology, it would be possible to determine a person's identity without the need to stop and ask them in the street, or even alert them that their identity is being checked and logged. The systems can check many thousands of faces in a database in under a second.
This combination of CCTV with facial recognition technology has been tried as a form of mass surveillance, but has been ineffective because of the low discriminating power of facial recognition technology and the very high number of false positives generated.
The latest developments in CCTV and imaging techniques, being developed in the UK and USA, is developing computerised monitoring so that the CCTV operator does not have to endlessly look at all the screens. This also means that an operator can run many more CCTV cameras. These systems do not observe people directly. Instead they track their behaviour by looking for particular types of movement, or particular types of clothing or baggage. The theory behind this notes that in public spaces people behave in set and predictable ways. People who are not part of the 'crowd', for example car thieves, do not behave in the same way. The computer can identify their movements, and alert the operator that they are acting out of the ordinary. Potentially, waiting in a busy street to meet someone could trigger this system.
The same type of system can, if required, go one step further and track an identified individual as they move through the area covered by CCTV. This is currently being developed in the USA as part of the project co-funded by the US Defense Advanced Research Projects Agency. With software tools, the system will be able to develop three-dimensional models of an area and track/monitor the movement of objects within it.
To many, the development of CCTV in public areas, linked to computer databases of people's pictures and identity, presents a serious breach of civil liberties. Critics fear the possibility that one would not be able to meet anonymously in a public place or drive and walk anonymously around a city. Demonstrations or assemblies in public places could be affected as the state would be able to collate lists of those leading them, taking part, or even just talking with protesters in the street.
- Sousveillance (inverse surveillance)
- Automatic number plate recognition (ANPR)
- Privacy International
- Anti-CCTV campaign
- Privacy International CCTV information
- UK Government pro-CCTV campaign
- The Register story: Face recognition useless for crowd surveillance
- Stefanos Pantagis: Sousveillance Underground and "Shooting Blind" Sousveillance projects
- The New York Surveillance Camera Players -- anti-CCTV group
- URBANEYE - A social research project on CCTV in Europe
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