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{{dablink|This article refers to a surveillance system. For other uses see [[CCTV]].}}
Sorry Mike
[[Image:Three Surveillance cameras.jpg|thumb|Surveillance cameras.]]

'''Closed Circuit Television''' ('''CCTV''') is the use of [[video camera]]s to transmit signal to a specific, limited set of monitors. It differs from [[broadcast television]] in that the signal is not openly transmitted, though it may employ point to point wireless links. CCTV is often used for [[surveillance]] in areas which need monitoring, such as [[bank]]s, [[casino]]s, [[airport]]s, military installations and convenience stores. Increasing use of CCTV in public places has caused debate over public [[surveillance]] versus [[privacy]]. In industrial plants, CCTV equipment may be used to observe parts of a process that are remote from a control room, or where the environment is not comfortable for humans. CCTV systems may operate continuously or only as required to monitor a particular event.

== History ==
[[Image:Video surveillance sign.jpg|thumb|right|Sign warning that premises are watched by CCTV cameras.]]

The first CCTV system was installed by [[Siemens AG]] at [[Test Stand VII]] in [[Peenemünde]] Germany in 1942, for observing the launch of [[V2 rocket|V2]]-rockets.<ref name="dornberger">[[Walter Dornberger|Dornberger, Walter]]: ''V-2'', [[Ballantine Books]] 1954, ASIN: B000P6L1ES, page 14.</ref> The noted German engineer [[Walter Bruch]] was responsible for the design and installation of the system.{{Fact|date=October 2007}} CCTV recording systems are often used at modern launch sites to record the flight of the rockets, in order to find the possible causes of malfunctions,{{Fact|date=October 2007}} while larger rockets are often fitted with CCTV allowing pictures of stage separation to be transmitted back to earth by radio link.{{Fact|date=October 2007}}

==Industrial processes==
Industrial processes which take place under conditions dangerous for humans are today often supervised by CCTV. These are mainly processes in the chemical industry, the interior of reactors or facilities for manufacture of nuclear fuel. Use of [[thermographic camera]]s allow operators to measure the [[temperature]] of the processes. The usage of CCTV in such processes is sometimes required by law.{{Fact|date=March 2008}}

== Crime registration ==
[[Image:Eric harris dylan klebold.jpg|thumb|right|[[Eric Harris and Dylan Klebold]], during the [[Columbine High School Massacre]].]]

CCTV for use outside government special facilities 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.
Surveillance of public areas in the [[United Kingdom]] by CCTV was developed partly in response to [[Provisional Irish Republican Army|IRA]] bombings. 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<ref>[http://www.urbaneye.net/results/ue_wp6.pdf http://www.urbaneye.net/]</ref>, based on a small sample in [[Putney]] High Street, estimated the number of surveillance cameras in private premises in London is around 500,000 and the total number of cameras in the UK is around 4,200,000. The UK has one camera for every 14 people.

There is virtually no evidence that CCTV deters crime.<ref>{{cite news|url=http://www.abcnews.go.com/US/Story?id=3360287&page=1|title=Eye on the City: Do Cameras Reduce Crime?|work=ABC News|first=Marcus|last=Baram|date=[[2007-07-09]]|accessdate=2007-07-10}}</ref> One effect that has been noted is a marginal reduction of crime when used in [[car park]]s, but that effect is short-lived. There are several good reasons to use CCTV, but deterrence is not among them. In London, "Police are no more likely to catch offenders in areas with hundreds of cameras than in those with hardly any." <ref>
[http://www.thisislondon.co.uk/news/article-23412867-details/Tens+of+thousands+of+CCTV+cameras%2C+yet+80%25+of+crime+unsolved/article.do "Tens of thousands of CCTV cameras, yet 80% of crime unsolved"] by Justin Davenport 2007
</ref> However, it has been argued that even when not preventing crimes cameras make it easier to solve them.<ref name="SMILE"/>

Cameras have also been installed in [[taxicab|taxi]]s in the hope of deterring violence against drivers <ref>"[http://news.bbc.co.uk/1/hi/england/hereford/worcs/3101016.stm CCTV to drive down cab attacks]," ''[[BBC]]''</ref><ref>[http://news.bbc.co.uk/1/hi/england/bristol/4295859.stm Taxi CCTV cameras are installed]," ''[[BBC]]''</ref>, and in mobile police surveillance vans.<ref>[http://news.bbc.co.uk/1/hi/england/tees/3529305.stm CCTV patrols to monitor estates]," ''[[BBC]]''</ref> In some cases CCTV cameras have become a target of attacks themselves.<ref>"[http://news.bbc.co.uk/1/hi/wales/south_east/3676550.stm http://news.bbc.co.uk/]," ''[[BBC]]''</ref> [[Middlesbrough]] council have recently installed "[[Talking CCTV]]" cameras in their busy town-centre.<ref>"[http://news.bbc.co.uk/2/hi/uk_news/england/tees/5353538.stm CCTV mast destroyed by vandals]," ''[[BBC]]''</ref> It is a system pioneered in [[Wiltshire]] which allows CCTV operators to communicate directly with the offenders they spot.<ref name="wiltshire">"[http://news.bbc.co.uk/2/hi/uk_news/england/wiltshire/2933626.stm Talking CCTV pioneered in Wiltshire]," ''[[BBC]]'', [[23 March]], [[2003]]</ref>

[[Image:Bulger cctv.jpg|right|tumb|The two-year-old [[Murder of James Bulger|Jamie Bulger]] being led away by his killers, recorded on shopping centre CCTV.]]

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]].<ref>"[http://news.bbc.co.uk/1/hi/world/americas/1865828.stm You're being watched, New York!]," ''[[BBC]]''</ref> There are 2,200 CCTV systems in [[Chicago]].<ref>"[http://web.archive.org/web/20070325081308/http://www.suntimes.com/news/metro/201612,CST-NWS-contro08.article Is Chicago safe from a terrorist attack?]," ''[[Chicago Sun-Times]]''</ref>

[[Image:Londonbombing2.jpg||thumb|left|The men alleged to be responsible for the [[7 July 2005 London bombings|7 July attacks on London]], captured on CCTV.]]

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 [[Murder of James Bulger|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.{{Fact|date=August 2007}} After the [[7 July 2005 London bombings|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]], [[2005]], [[Jean Charles de Menezes]] was shot dead by police at [[Stockwell tube station]]. CCTV footage has debunked some police claims.<ref>"[http://news.bbc.co.uk/1/hi/uk/4293462.stm Menezes family view CCTV footage]," ''[[BBC]]''</ref> Because of the [[21 July 2005 London bombings|bombing attempts the previous day]], some of the tapes had been supposedly removed from CCTV cameras for study, and they were not functional.<ref>"[http://news.bbc.co.uk/1/hi/uk/4175688.stm Menezes death 'cover-up' doubted]," ''[[BBC]]''</ref> The use of [[personal video recorder|DVR]] technology may solve this problem.<ref>"[http://news.bbc.co.uk/1/hi/england/2070312.stm Digital CCTV scheme switches on]," ''[[BBC]]''</ref>

== Monitoring for safety ==
A CCTV system may be installed where an operator of a machine cannot directly observe people who may be injured by unexpected machine operation. For example, on a subway train, CCTV cameras may allow the operator to confirm that people are clear of doors before closing them and starting the train. Operators of an amusement park ride may use a CCTV system to observe that people are not endangered by starting the ride. A CCTV camera and dashboard monitor can make reversing a vehicle safer, if it allows the driver to observe objects or people not otherwise visible.

== Closed Circuit Digital Photography (CCDP)==
{{seealso|Closed-circuit television camera}}
A development in the world of CCTV (October 2005) is in the use of megapixel digital still cameras that can take 1600 x 1200 pixel resolution images of the camera scene either on a time lapse or motion detection basis. Images taken with a digital still camera have higher resolution than those taken with a typical video camera. Relatively low-cost digital still cameras can be used for CCTV purposes, using CCDP software that controls the camera from the PC.

Images of the camera scene are transferred automatically to a computer every few seconds. Images may be monitored remotely if the computer is connected to a network.

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. Many of these cameras however, are owned by private companies and transmit data to drivers' [[GPS]] systems.

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.

== Privacy ==
{{main|Privacy}}
[[Image:SoMSurveillance .jpg|thumb|left|A [[surveillance]] room being surveilled itself.]]
[[Image:Wfm cctv van.jpg|thumb|right|A mobile closed-circuit TV van monitoring a street market.]]

Opponents of CCTV point out the loss of [[privacy]] of the people under surveillance, and the negative impact of surveillance on [[civil liberty|civil liberties]]. Furthermore, they argue that CCTV displaces crime, rather than reducing it. Critics often dub CCTV as "[[Big Brother (1984)|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. The apartment in which George Orwell wrote now has 32 CCTV cameras within 200 yards of it.

More positive views of CCTV cameras have argued that the cameras are not intruding into people's privacy, as they are not surveilling private, but ''public'' space, where an individual's right to privacy can reasonably be weighted against the public's need for protection.<ref name="SMILE">''Smile, the cameras are here to watch over you'' - ''[[The New Zealand Herald]]'', Tuesday 18 March 2008, Page A14</ref>

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. However, since the events of September 11, many studies have suggested that public opinion of CCTV has grown more favorable[http://abcnews.go.com/US/Story?id=3422372&page=1]. Many proponents of CCTV cite the attacks of the London Underground bombings as one example of how effective surveillance led to swift progress in post-event investigations.
Quite apart from government-permitted use (or abuse), questions are also raised about illegal access to CCTV recordings. The [[Data Protection Act 1998]] in the [[United Kingdom]] led to legal restrictions on the uses of CCTV recordings, 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 recordings. However subsequent case law (Durant vs. FSA) has limited the scope of the protection provided by this law, and not all CCTV systems are currently regulated.<ref>[http://www.informationcommissioner.gov.uk/eventual.aspx?id=5739 http://www.informationcommissioner.gov.uk/]</ref>

A 2007 report by the UK's [[Information Commissioner's Office (UK)|Information Commissioner's Office]], highlighted the need for the public to be made more aware of the "creeping encroachment" into their civil liberties created by the growing use of surveillance apparatus. A year prior to the report [[Richard Thomas (Information Commissioner)|Richard Thomas]], the Information Commissioner, warned that Britain was "sleepwalking into a surveillance society".<ref>The Independent: Britain becoming a Big Brother society, says data watchdog
[http://news.independent.co.uk/uk/this_britain/article2494230.ece]</ref>

In 2007, the UK watchdog CameraWatch claimed that the majority of CCTV cameras in the UK are operated illegally or are in breach of privacy guidelines. In response, the Information Office denied the claim adding that any reported abuses of the Data Protection Act are swiftly investigated. <ref> Telegraph.co.uk: Majority of UK's CCTV cameras 'are illegal' [http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/05/31/ncamera131.xml]</ref>

In the [[United States]] there are no such data protection mechanisms. It has been questioned whether CCTV evidence is allowable under the [[Fourth Amendment to the United States Constitution|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.{{Fact|date=June 2007}} In [[Ontario]], both the ''municipal'' and ''provincial'' versions of the [http://www.ipc.on.ca/index.asp?navid=73 Freedom of Information and Protection of Privacy Act] outline very specific guidelines that control how ''[[images]]'' and ''[[information]]'' can be gathered by this method and/or released.

== More recent developments ==
[[Image:closed.circuit.camera.arp.750pix.jpg|thumb|right|Surveillance camera at London (Heathrow) Airport.]]

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.

[[Image:Mcdonaldscamera.JPG|thumb|left|Surveillance camera outside a McDonalds highway drive-in.]]

There is no technological limitation preventing a [[computer network|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.<ref>[http://news.bbc.co.uk/1/hi/england/2865949.stm http://news.bbc.co.uk/]</ref>

CCTV critics see the most disturbing extension to this technology as the [[facial recognition system|recognition of faces]] from high-definition CCTV images. This could determine a persons identity without alerting him that his identity is being checked and logged. The systems can check many thousands of faces in a database in under a second. The combination of CCTV and facial recognition 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 [[Type I and type II errors|false positive]]s generated. This type of system has been proposed to compare faces at airports and seaports with those of suspected terrorists or other undesirable entrants.

[[Image:Eye-in-the-sky083.jpg|thumb|right|Eye-in-the-sky surveillance dome camera watching from a high steel pole.]]

Computerized monitoring of CCTV images is under development, so that a human CCTV operator does not have to endlessly look at all the screens, allowing an operator to observe many more CCTV cameras. These systems do not observe people directly. Instead they track their behaviour by looking for particular types of body movement behavior, 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. Recently in the latter part of 2006, news reports on UK television brought to light new technology developed which uses microphones in conjunction with CCTV. If a person is observed to be shouting in an aggressive manner (i.e., provoking a fight), the camera can automatically zoom in and pinpoint the individual and alert a camera operator. Of course this then lead to the discussion that the technology can also be used to eavesdrop and record private conversations from a reasonable distance (e.g., 100 metres or about 330 feet).

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.

== Retention, storage and preservation ==
The long-term storage and archiving of CCTV recordings is an issue of concern in the implementation of a CCTV system. Re-usable media such as tape may be cycled through the recording process at regular intervals. There also may be statutory limits on retention of data under some sort of [[Data Protection Act]]. However, individual recordings may be retained for indefinite periods for use in investigations or as evidence in legal proceedings.

Recordings are kept for several purposes. Firstly, the primary purpose for which they were created (e.g., to monitor a facility). Secondly, they need to be preserved for a reasonable amount of time to recover any evidence of other important activity they might document (e.g., a group of people passing a facility the night a crime was committed). Finally, the recordings may be evaluated for historical, research or other long-term information of value they may contain (e.g., samples kept to help understand trends for a business or community).

Recordings are more commonly stored using hard disk drives in lieu of video cassette recorders. The quality of digital recordings are subject to compression ratios, images stored per second, image size and duration of image retention before being overwritten. Different vendors of digital video recorders use different compression standards and varying compression ratios. However, the following guide can be used to help determine hard disk capacity;
* Determine the numbers of cameras (N<sub>c</sub>).
* Determine the frame rate (frames per second) at which each camera will be recorded at (R<sub>f</sub>).
* Determine the average size (in Kilobytes) that each compressed frame of video will take up on the hard disk (S<sub>f</sub>), after the compression ratio has been applied.
* Approximate the activity (in percentage) time each camera will be recording at the above frame rate (A).
* Determine the duration (in days) that video from each camera will be retained (D).

Once these values are determined, the following formula can be used to determine the HDD capacity;

<math>Capacity(Gigabytes)=\frac{N_{c}\times((R_{f}\times S_{f}\times A)\times((60\times 60\times 24)\times D))}{1024^2}</math>

==Special uses==
[[Image:Cctvspeakers.jpg|thumb|right|150px|An example of a CCTV camera with speakers attached, in [[Ipswich]], [[UK]]]]
*A very special use of CCTV is at [[Hessdalen AMS]] where by it is used for discovery of unidentified flying objects.
*In the earlier days of television, some programs, and selected live sporting events, were shown on closed-circuit television in theaters across the United States. From 1965-1970, the [[Indianapolis 500]] was shown live on closed-circuit television in many movie theatres. The first few [[WrestleMania]] events were shown in such a way as well.
* In the UK, some places have installed [[talking CCTV]], where the operator can talk to the people they monitor.

== CCTV countermeasures ==

Unless physically protected, CCTV cameras have been found to be vulnerable against a variety of (mostly illegal) tactics:

*Some people will deliberately destroy cameras.<ref>[http://rtmark.com/cctv http://rtmark.com/]</ref> Some outdoor cameras, such as those employed by the Chicago Police Department, have bullet-resistant housing.{{Fact|date=March 2008}}
*Spraying substances over the lens can make the image too blurry to be read.
*[[Laser pointer]]s can temporarily blind cameras,<ref>[http://naimark.net/projects/zap/howto.html http://naimark.net/]</ref> and higher powered lasers can damage them. However, since lasers are monochromatic, colour filters can reduce the effect of laser pointers.
*For wireless networks, broadcasting a signal at the same frequency of the CCTV network is reported to be able to jam it.{{Fact|date=February 2008}}

== CCTV cameras in popular culture ==
The difficulty of avoiding CCTV detection often appears in games and films.

*In the film [[The Bourne Ultimatum (film)]] the CIA uses British CCTV cameras to track Jason Bourne and a reporter through a train station ([[Waterloo station|Waterloo]]).
*In the computer game ''[[Duke Nukem II]]'', the player earns bonus points for destroying all the security cameras in a level.
*In films like ''[[Speed (film)|Speed]]'' and ''[[Mission: Impossible III]]'', CCTV is defeated by tricking it into playing looping recordings.
*In the flim '''Oceans11''' the hero team dodges a set of Video Surveillance Syetems and steals a Casino Chest.
*In the game ''[[Hitman: Blood Money]]'', the player can prevent penalties by stealing tapes of CCTV recordings that may have picked [[Agent 47]] up.
*In the [[Nintendo 64]] video game ''[[GoldenEye 007]]'', higher settings of difficulty yield higher numbers of CCTV security cameras; detection results in triggered alarms, bringing guards. Other security cameras are mounted with machine guns, and can differentiate between the player (Bond) and enemy personnel when firing. To make matters worse, these combination cameras/automatic guns are often mounted in areas of little cover and low visibility. Often the destruction of CCTV cameras are a required objective.
*In the [[Splinter Cell]] video game series, CCTV cameras and how the player interacts with them play a large role in the game. If a player is caught on one, an alarm will sound, and if a player destroys one, nearby guards will notice and sound an alarm anyway. In addition, the player is able to plant small CCTV cameras called "sticky cameras".
*The song 'Watching You' from the eponymous debut album by British rock band [[Alien Stash Tin]] is about the growth of CCTV culture.
*The [[Metal Gear Solid]] Series often uses CCTV cameras. Some of which are mounted with machine guns which fire at Snake when he passes in front of them. Others just trigger the alarm. Snake is able to defeat CCTV cameras either by destroying them with missiles or firearms, hiding from them using cardboard boxes, or jamming them with chaff grenades.
*''[[Stars of CCTV]]'', the debut album from Staines-based British band ''[[HARD-Fi]]'', was nominated for the 2005 ''[[Mercury Music Prize]]''.
*In the British TV Show [[Torchwood]], the characters frequently hack into Cardiff's CCTV to investigate alien threats.
*In the game ''[[Portal (video game)]]'', the player receives an achievement for detaching all the security cameras from the wall.
*In the British television drama series [[Spooks]], CCTV is frequently accessed and used by MI5 to find the whereabouts of terrorists and monitor various situations.

==See also==
[[Image:CCTV Advisory Sign - Severn Trent Water - Birmingham - 2005-10-14.jpg|thumb|right|CCTV advisory notice - the [[Information Commissioner's Office (UK)|Information Commissioner's Office]] places a requirement for use-signage on certain classes of CCTV in the UK.]]
* [[Closed-circuit television camera]]
* [[Surveillance]]
* [[Big Brother (TV series)|Big Brother]]
* [[Fake Security Camera]]
* [[Bugging]]
* [[Sousveillance|Sousveillance (inverse surveillance)]]
* [[Privacy International]]
* [[Eye in the sky]]
* [[Physical security]]
* [[Telescreen]]
*[[Proprietary DVR]]

==References==
{{Reflist}}

==External links==
{{commonscat|Security cameras}}
* [http://www.securityinfowatch.com/online/The-Latest/CCTV-and-Civil-Liberties-after-the-London-Terror-Attacks/5014SIW306 CCTV and Civil Liberties after the London Terror Attacks]
* [http://www.crimereduction.gov.uk/cctvminisite4.htm UK Government pro-CCTV campaign]
* [http://www.AMW1.com Oxford Street CCTV images]
* [http://www.homeoffice.gov.uk/rds/pdfs05/hors292.pdf Assessing the Impact of CCTV, a UK Home office study on the effectiveness of closed-circuit television]
* [http://www.theregister.co.uk/2001/09/27/face_recognition_useless_for_crowd/ The Register story: Face recognition useless for crowd surveillance]
* [http://www.ico.gov.uk/Home/for_organisations/topic_specific_guides/cctv.aspx CCTV Guidance notes] from the UK [[Information Commissioner's Office (UK)|Information Commissioner's Office]]
*[http://archives.cbc.ca/IDD-1-75-1299/science_technology/police_cameras_privacy/ CBC Digital Archives - The Long Lens of the Law]
*[http://www.urbaneye.net/ The Urbaneye Project on CCTV in Europe]
* [http://www.ncjrs.gov/pdffiles1/jr000249d.pdf CCTV:Constant Cameras Track Violators] National Institute of Justice Journal 249 (2003). Washington, DC: U.S. Department of Justice.
* [http://www.everystepyoutake.org "Every Step You Take"]: An independent documentary film about CCTV in the United Kingdom.

[[Category:Applications of computer vision]]
[[Category:Surveillance]]
[[Category:Television terminology]]

[[ca:Circuit tancat de televisió]]
[[de:Videoüberwachungsanlage]]
[[es:Circuito cerrado de televisión]]
[[fr:Caméra de surveillance]]
[[he:טלוויזיה במעגל בסגור]]
[[nl:Cameratoezicht]]
[[ja:監視カメラ]]
[[no:CCTV]]
[[pl:Telewizja przemysłowa]]
[[sv:Kameraövervakning]]
[[fi:Valvontakamera]]
[[zh:閉路電視]]

Revision as of 16:52, 3 April 2008

Surveillance cameras.

Closed Circuit Television (CCTV) is the use of video cameras to transmit signal to a specific, limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point to point wireless links. CCTV is often used for surveillance in areas which need monitoring, such as banks, casinos, airports, military installations and convenience stores. Increasing use of CCTV in public places has caused debate over public surveillance versus privacy. In industrial plants, CCTV equipment may be used to observe parts of a process that are remote from a control room, or where the environment is not comfortable for humans. CCTV systems may operate continuously or only as required to monitor a particular event.

History

Sign warning that premises are watched by CCTV cameras.

The first CCTV system was installed by Siemens AG at Test Stand VII in Peenemünde Germany in 1942, for observing the launch of V2-rockets.[1] The noted German engineer Walter Bruch was responsible for the design and installation of the system.[citation needed] CCTV recording systems are often used at modern launch sites to record the flight of the rockets, in order to find the possible causes of malfunctions,[citation needed] while larger rockets are often fitted with CCTV allowing pictures of stage separation to be transmitted back to earth by radio link.[citation needed]

Industrial processes

Industrial processes which take place under conditions dangerous for humans are today often supervised by CCTV. These are mainly processes in the chemical industry, the interior of reactors or facilities for manufacture of nuclear fuel. Use of thermographic cameras allow operators to measure the temperature of the processes. The usage of CCTV in such processes is sometimes required by law.[citation needed]

Crime registration

File:Eric harris dylan klebold.jpg
Eric Harris and Dylan Klebold, during the Columbine High School Massacre.

CCTV for use outside government special facilities 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. Surveillance of public areas in the United Kingdom by CCTV was developed partly in response to IRA bombings. 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[2], based on a small sample in Putney High Street, estimated the number of surveillance cameras in private premises in London is around 500,000 and the total number of cameras in the UK is around 4,200,000. The UK has one camera for every 14 people.

There is virtually no evidence that CCTV deters crime.[3] One effect that has been noted is a marginal reduction of crime when used in car parks, but that effect is short-lived. There are several good reasons to use CCTV, but deterrence is not among them. In London, "Police are no more likely to catch offenders in areas with hundreds of cameras than in those with hardly any." [4] However, it has been argued that even when not preventing crimes cameras make it easier to solve them.[5]

Cameras have also been installed in taxis in the hope of deterring violence against drivers [6][7], and in mobile police surveillance vans.[8] In some cases CCTV cameras have become a target of attacks themselves.[9] Middlesbrough council have recently installed "Talking CCTV" cameras in their busy town-centre.[10] It is a system pioneered in Wiltshire which allows CCTV operators to communicate directly with the offenders they spot.[11]

The two-year-old Jamie Bulger being led away by his killers, recorded on shopping centre CCTV.
The two-year-old Jamie Bulger being led away by his killers, recorded on shopping centre CCTV.

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.[12] There are 2,200 CCTV systems in Chicago.[13]

File:Londonbombing2.jpg
The men alleged to be responsible for the 7 July attacks on London, captured on CCTV.

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.[citation needed] 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, 2005, Jean Charles de Menezes was shot dead by police at Stockwell tube station. CCTV footage has debunked some police claims.[14] Because of the bombing attempts the previous day, some of the tapes had been supposedly removed from CCTV cameras for study, and they were not functional.[15] The use of DVR technology may solve this problem.[16]

Monitoring for safety

A CCTV system may be installed where an operator of a machine cannot directly observe people who may be injured by unexpected machine operation. For example, on a subway train, CCTV cameras may allow the operator to confirm that people are clear of doors before closing them and starting the train. Operators of an amusement park ride may use a CCTV system to observe that people are not endangered by starting the ride. A CCTV camera and dashboard monitor can make reversing a vehicle safer, if it allows the driver to observe objects or people not otherwise visible.

Closed Circuit Digital Photography (CCDP)

A development in the world of CCTV (October 2005) is in the use of megapixel digital still cameras that can take 1600 x 1200 pixel resolution images of the camera scene either on a time lapse or motion detection basis. Images taken with a digital still camera have higher resolution than those taken with a typical video camera. Relatively low-cost digital still cameras can be used for CCTV purposes, using CCDP software that controls the camera from the PC.

Images of the camera scene are transferred automatically to a computer every few seconds. Images may be monitored remotely if the computer is connected to a network.

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. Many of these cameras however, are owned by private companies and transmit data to drivers' GPS systems.

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.

Privacy

A surveillance room being surveilled itself.
A mobile closed-circuit TV van monitoring a street market.

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. The apartment in which George Orwell wrote now has 32 CCTV cameras within 200 yards of it.

More positive views of CCTV cameras have argued that the cameras are not intruding into people's privacy, as they are not surveilling private, but public space, where an individual's right to privacy can reasonably be weighted against the public's need for protection.[5]

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. However, since the events of September 11, many studies have suggested that public opinion of CCTV has grown more favorable[3]. Many proponents of CCTV cite the attacks of the London Underground bombings as one example of how effective surveillance led to swift progress in post-event investigations.

Quite apart from government-permitted use (or abuse), questions are also raised about illegal access to CCTV recordings. The Data Protection Act 1998 in the United Kingdom led to legal restrictions on the uses of CCTV recordings, 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 recordings. However subsequent case law (Durant vs. FSA) has limited the scope of the protection provided by this law, and not all CCTV systems are currently regulated.[17]

A 2007 report by the UK's Information Commissioner's Office, highlighted the need for the public to be made more aware of the "creeping encroachment" into their civil liberties created by the growing use of surveillance apparatus. A year prior to the report Richard Thomas, the Information Commissioner, warned that Britain was "sleepwalking into a surveillance society".[18]

In 2007, the UK watchdog CameraWatch claimed that the majority of CCTV cameras in the UK are operated illegally or are in breach of privacy guidelines. In response, the Information Office denied the claim adding that any reported abuses of the Data Protection Act are swiftly investigated. [19]

In the United States there are 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.[citation needed] In Ontario, both the municipal and provincial versions of the Freedom of Information and Protection of Privacy Act outline very specific guidelines that control how images and information can be gathered by this method and/or released.

More recent developments

Surveillance camera at London (Heathrow) Airport.

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.

Surveillance camera outside a McDonalds highway drive-in.

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.[20]

CCTV critics see the most disturbing extension to this technology as the recognition of faces from high-definition CCTV images. This could determine a persons identity without alerting him that his identity is being checked and logged. The systems can check many thousands of faces in a database in under a second. The combination of CCTV and facial recognition 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 been proposed to compare faces at airports and seaports with those of suspected terrorists or other undesirable entrants.

Eye-in-the-sky surveillance dome camera watching from a high steel pole.

Computerized monitoring of CCTV images is under development, so that a human CCTV operator does not have to endlessly look at all the screens, allowing an operator to observe many more CCTV cameras. These systems do not observe people directly. Instead they track their behaviour by looking for particular types of body movement behavior, 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. Recently in the latter part of 2006, news reports on UK television brought to light new technology developed which uses microphones in conjunction with CCTV. If a person is observed to be shouting in an aggressive manner (i.e., provoking a fight), the camera can automatically zoom in and pinpoint the individual and alert a camera operator. Of course this then lead to the discussion that the technology can also be used to eavesdrop and record private conversations from a reasonable distance (e.g., 100 metres or about 330 feet).

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.

Retention, storage and preservation

The long-term storage and archiving of CCTV recordings is an issue of concern in the implementation of a CCTV system. Re-usable media such as tape may be cycled through the recording process at regular intervals. There also may be statutory limits on retention of data under some sort of Data Protection Act. However, individual recordings may be retained for indefinite periods for use in investigations or as evidence in legal proceedings.

Recordings are kept for several purposes. Firstly, the primary purpose for which they were created (e.g., to monitor a facility). Secondly, they need to be preserved for a reasonable amount of time to recover any evidence of other important activity they might document (e.g., a group of people passing a facility the night a crime was committed). Finally, the recordings may be evaluated for historical, research or other long-term information of value they may contain (e.g., samples kept to help understand trends for a business or community).

Recordings are more commonly stored using hard disk drives in lieu of video cassette recorders. The quality of digital recordings are subject to compression ratios, images stored per second, image size and duration of image retention before being overwritten. Different vendors of digital video recorders use different compression standards and varying compression ratios. However, the following guide can be used to help determine hard disk capacity;

  • Determine the numbers of cameras (Nc).
  • Determine the frame rate (frames per second) at which each camera will be recorded at (Rf).
  • Determine the average size (in Kilobytes) that each compressed frame of video will take up on the hard disk (Sf), after the compression ratio has been applied.
  • Approximate the activity (in percentage) time each camera will be recording at the above frame rate (A).
  • Determine the duration (in days) that video from each camera will be retained (D).

Once these values are determined, the following formula can be used to determine the HDD capacity;

Special uses

An example of a CCTV camera with speakers attached, in Ipswich, UK
  • A very special use of CCTV is at Hessdalen AMS where by it is used for discovery of unidentified flying objects.
  • In the earlier days of television, some programs, and selected live sporting events, were shown on closed-circuit television in theaters across the United States. From 1965-1970, the Indianapolis 500 was shown live on closed-circuit television in many movie theatres. The first few WrestleMania events were shown in such a way as well.
  • In the UK, some places have installed talking CCTV, where the operator can talk to the people they monitor.

CCTV countermeasures

Unless physically protected, CCTV cameras have been found to be vulnerable against a variety of (mostly illegal) tactics:

  • Some people will deliberately destroy cameras.[21] Some outdoor cameras, such as those employed by the Chicago Police Department, have bullet-resistant housing.[citation needed]
  • Spraying substances over the lens can make the image too blurry to be read.
  • Laser pointers can temporarily blind cameras,[22] and higher powered lasers can damage them. However, since lasers are monochromatic, colour filters can reduce the effect of laser pointers.
  • For wireless networks, broadcasting a signal at the same frequency of the CCTV network is reported to be able to jam it.[citation needed]

CCTV cameras in popular culture

The difficulty of avoiding CCTV detection often appears in games and films.

  • In the film The Bourne Ultimatum (film) the CIA uses British CCTV cameras to track Jason Bourne and a reporter through a train station (Waterloo).
  • In the computer game Duke Nukem II, the player earns bonus points for destroying all the security cameras in a level.
  • In films like Speed and Mission: Impossible III, CCTV is defeated by tricking it into playing looping recordings.
  • In the flim Oceans11 the hero team dodges a set of Video Surveillance Syetems and steals a Casino Chest.
  • In the game Hitman: Blood Money, the player can prevent penalties by stealing tapes of CCTV recordings that may have picked Agent 47 up.
  • In the Nintendo 64 video game GoldenEye 007, higher settings of difficulty yield higher numbers of CCTV security cameras; detection results in triggered alarms, bringing guards. Other security cameras are mounted with machine guns, and can differentiate between the player (Bond) and enemy personnel when firing. To make matters worse, these combination cameras/automatic guns are often mounted in areas of little cover and low visibility. Often the destruction of CCTV cameras are a required objective.
  • In the Splinter Cell video game series, CCTV cameras and how the player interacts with them play a large role in the game. If a player is caught on one, an alarm will sound, and if a player destroys one, nearby guards will notice and sound an alarm anyway. In addition, the player is able to plant small CCTV cameras called "sticky cameras".
  • The song 'Watching You' from the eponymous debut album by British rock band Alien Stash Tin is about the growth of CCTV culture.
  • The Metal Gear Solid Series often uses CCTV cameras. Some of which are mounted with machine guns which fire at Snake when he passes in front of them. Others just trigger the alarm. Snake is able to defeat CCTV cameras either by destroying them with missiles or firearms, hiding from them using cardboard boxes, or jamming them with chaff grenades.
  • Stars of CCTV, the debut album from Staines-based British band HARD-Fi, was nominated for the 2005 Mercury Music Prize.
  • In the British TV Show Torchwood, the characters frequently hack into Cardiff's CCTV to investigate alien threats.
  • In the game Portal (video game), the player receives an achievement for detaching all the security cameras from the wall.
  • In the British television drama series Spooks, CCTV is frequently accessed and used by MI5 to find the whereabouts of terrorists and monitor various situations.

See also

File:CCTV Advisory Sign - Severn Trent Water - Birmingham - 2005-10-14.jpg
CCTV advisory notice - the Information Commissioner's Office places a requirement for use-signage on certain classes of CCTV in the UK.

References

  1. ^ Dornberger, Walter: V-2, Ballantine Books 1954, ASIN: B000P6L1ES, page 14.
  2. ^ http://www.urbaneye.net/
  3. ^ Baram, Marcus (2007-07-09). "Eye on the City: Do Cameras Reduce Crime?". ABC News. Retrieved 2007-07-10. {{cite news}}: Check date values in: |date= (help)
  4. ^ "Tens of thousands of CCTV cameras, yet 80% of crime unsolved" by Justin Davenport 2007
  5. ^ a b Smile, the cameras are here to watch over you - The New Zealand Herald, Tuesday 18 March 2008, Page A14
  6. ^ "CCTV to drive down cab attacks," BBC
  7. ^ Taxi CCTV cameras are installed," BBC
  8. ^ CCTV patrols to monitor estates," BBC
  9. ^ "http://news.bbc.co.uk/," BBC
  10. ^ "CCTV mast destroyed by vandals," BBC
  11. ^ "Talking CCTV pioneered in Wiltshire," BBC, 23 March, 2003
  12. ^ "You're being watched, New York!," BBC
  13. ^ "Is Chicago safe from a terrorist attack?," Chicago Sun-Times
  14. ^ "Menezes family view CCTV footage," BBC
  15. ^ "Menezes death 'cover-up' doubted," BBC
  16. ^ "Digital CCTV scheme switches on," BBC
  17. ^ http://www.informationcommissioner.gov.uk/
  18. ^ The Independent: Britain becoming a Big Brother society, says data watchdog [1]
  19. ^ Telegraph.co.uk: Majority of UK's CCTV cameras 'are illegal' [2]
  20. ^ http://news.bbc.co.uk/
  21. ^ http://rtmark.com/
  22. ^ http://naimark.net/

External links