Closed-circuit television
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- "CCTV" redirects here. For , see .
Closed-circuit television (CCTV) is the use of television cameras to transmit a signal to a specific, limited set of monitors. It differs from broadcast television in that all components are directly linked, and that the signal is not openly transmitted, though it may employ point to point wireless links. CCTV is often used for surveillance in areas where there is an increased need for security, such as banks, casinos, and airports. They may also have military uses. The use of CCTVs in public places has increased, causing debate over security versus privacy.
CCTV was developed as a means of increasing security in banks. Today it has developed to the point where it is simple and inexpensive enough to be used in home security systems, and for surveillance.
Crime prevention and detection
CCTV was developed partly in response to IRA bombings in the United Kingdom. Experiments in the UK during the 1970s and 1980s (including outdoor CCTV in Bournemouth in 1985), led to several larger trial programs in the early 1990s. These were deemed successful in the government report "CCTV: Looking Out For You", issued by the Home Office in 1994, and paved the way for a massive increase in the number of CCTV systems installed. Today, systems cover most town and city centres, and many stations, car-parks and estates. The exact number of CCTV cameras in the UK is not known but a 2002 working paper by Michael McCahill and Clive Norris of UrbanEye [link], based on a small sample in Putney High Street, "guesstimated" the number of surveillance cameras in private premises in London as around 400,000 and the total number of cameras in the UK as around 4,000,000. The UK has one camera for every 14 people.
Claims that they reduce or deter crime have not been clearly borne out by independent studies, though the government claims that when properly used they do result in deterrence, rather than displacement. One clear effect that has been noted is a reduction of car crime when used in car parks. Cameras have also been installed in taxis to deter violence against drivers [link] [link], and also in mobile police surveillance vans [link]. In some cases CCTV cameras have become a target of attacks themselves. [link]
The use of CCTV in the United States is less common, though increasing, and generally meets stronger opposition. In 1998 3,000 CCTV systems were found in New York City. [link]
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.
After the bombings of London on 7 July 2005, CCTV footage was used to identify the bombers. The media was surprised that few tube trains actually had CCTV cameras, and there were some calls for this to be increased.
On July 22, Jean Charles de Menezes was shot dead by police at Stockwell tube station. CCTV footage has debunked some police claims. [link] Because of the follow-up bombing attempts the previous day, some of the tapes had been supposedly removed from CCTV cameras for study, and they were not functional. [link] The use of DVR technology may solve this problem. [link]
Closed Circuit Digital Photography (CCDP)
- See also Closed-circuit television camera.
A development in the world of CCTV (October 2005) is in the use of megapixel digital stills cameras that can take 1600 x 1200 pixel resolution images of the camera scene either on a time lapse or motion detection basis.
The quality of images taken with a digital stills camera is excellent compared to video recordings captured using a video camera. Relatively low-cost digital stills cameras can be used for CCTV purposes as well as for taking holiday photos, using CCDP software that controls the camera from the PC.
The image resolution of many digital cameras is in the region of 6 million pixels, whereas the maximum resolution of most cctv video cameras is a mere 320,000 pixels. In situations where top quality surveillance images are required, it may pay to use a digital stills camera for security purposes, rather than a CCTV video camera.
Images of the camera scene are captured on a time-lapse or motion detection basis and transferred automatically to a PC or laptop using either a USB cable or a wireless adapter. It takes only a couple of seconds for even large 1MB images to be downloaded from the camera. If the laptop or PC is accessible over the internet then the camera window can be monitored live, although the real value of using digital stills cameras lies in the quality of the captured images and not in live monitoring.
Closed Circuit Digital Photography (CCDP) is more suited for capturing and saving recorded photographs, whereas Closed Circuit Television (CCTV)is more suitable for live monitoring purposes.
Traffic monitoring
Many cities and motorway networks have extensive traffic-monitoring systems, using closed-circuit television to detect congestion and notice accidents.The London congestion charge is enforced by cameras positioned at the boundaries of and inside the congestion charge zone, which automatically read the registration plates of cars. If the driver does not pay the charge then a fine will be imposed. Similar systems are being developed as a means of locating cars reported stolen.
Speed cameras are ostensibly to deter speeding, although critics have claimed they are often installed to generate revenue for the installing agent, who collects the fines.
Privacy
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. Critics often dub CCTV as "Big Brother surveillance", a reference to George Orwell's novel Nineteen Eighty-Four, which featured a two-way telescreen in every home through which The Party would monitor the populace. A more realistic depiction of CCTV is in the V for Vendetta series, which anticipated the current situation.
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, especially with the relationship to ASBOs.
Quite apart from government-permitted use (or abuse), questions are also raised about illegal access to CCTV footage. In May 2005 four were charged with use of CCTV for the purposes of voyeurism in Merseyside [link]. In December 2005, three of them were convicted. [link]
Previously a CCTV operator in Glamorgan was convicted on obscenity charges after making obscene phone calls to people he had been spying on. Other specific examples include a video Caught in the Act, released in 1996 which featured various couples having sex, captured on CCTV, and broadcast of footage of a man, Geoff Peck, attempting to commit suicide. [link], [link].
The Data Protection Act 1998 in the United Kingdom led to legal restrictions being imposed on the use to which CCTV footage can be put, and also mandated their registration with the Data Protection Agency. The successor to the DPA, the Information Commissioner in 2004 clarified that this required registration of all CCTV systems with the Commissioner, and prompt deletion of archived footage. However subsequent case law (Durant vs. FSA) has limited the scope of the legal protection provided by this law, and not all CCTV systems are currently regulated. [link]
In the United States there is no such data protection mechanisms. It has been questioned whether CCTV evidence is allowable under the Fourth Amendment which prohibits "unreasonable searches and seizures". The courts have generally not taken this view.
In Canada the use of video surveillance has grown exponentially. Disturbingly to some, corporations may legally record video even in changerooms. The Talisman Centre in Calgary, Alberta a fitness centre, has numerous video cameras in the men's changeroom that record men changing and showering.
Fears of technological developments
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.
The implementation of automatic number plate recognition 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. Reports have also been made of plate recognition misreading numbers leading to the billing of the entirely wrong people. [link]
CCTV critics see the most disturbing extension to this technology as 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. This type of system has generally been proposed to compare faces at airports and seaports with those of suspected terrorists or other undesirable entrants.
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 is that in public spaces people behave in 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.
The same type of system can track an identified individual as they move through the area covered by CCTV. This is 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.
See also
External links
- [Free tools for setting up CCTV Surveillance Systems]
- [New York Times article about "Surveillance Camera Players"]
- [UK Government pro-CCTV campaign]
- [The Register story: Face recognition useless for crowd surveillance]
- [CCTV Guidance notes] from the UK Information Commissioner's Office
- [CBC Digital Archives - The Long Lens of the Law]
- National Institute of Justice Journal 249. (2003).CCTV: Constant Cameras Track Violators Washington, DC: U.S. Department of Justice. http://www.ncjrs.gov/pdffiles1/jr000249d.pdf
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