Closed-circuit television

From Wikipedia, the free encyclopedia
  (Redirected from CCTV)
Jump to: navigation, search
"CCTV" redirects here. For the Chinese television network, see China Central Television. For closed-circuit screenings for an audience, see Public and private screening. For other uses, see CCTV (disambiguation).
Surveillance cameras on the corner of a building.
Dome CCTV cameras.

Closed-circuit television (CCTV) is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point to point (P2P), point to multipoint, or mesh wireless links. Though almost all video cameras fit this definition, the term is most often applied to those used for surveillance in areas that may need monitoring such as banks, casinos, airports, military installations, and convenience stores. Videotelephony is seldom called "CCTV" but the use of video in distance education, where it is an important tool, is often so called.[1][2]

In industrial plants, CCTV equipment may be used to observe parts of a process from a central control room, for example when the environment is not suitable for humans. CCTV systems may operate continuously or only as required to monitor a particular event. A more advanced form of CCTV, utilizing digital video recorders[3] (DVRs), provides recording for possibly many years, with a variety of quality and performance options and extra features (such as motion detection and email alerts). More recently, decentralized IP cameras, some equipped with megapixel sensors, support recording directly to network-attached storage devices, or internal flash for completely stand-alone operation. Surveillance of the public using CCTV is particularly common in many areas around the world. In recent years, the use of body worn video cameras has been introduced as a new form of surveillance.

History[edit]

Closed circuit TV in Munich, 1973 photo
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 V-2 rockets.[4] The noted German engineer Walter Bruch was responsible for the technological design and installation of the system.[note 1]

In the U.S. the first commercial closed-circuit television system became available in 1949, called Vericon. Very little is known about Vericon except it was advertised as not requiring a government permit.[8]

Technology[edit]

The earliest systems required constant monitoring because there was no way to record and store the information. Recording systems were introduced later, when primitive reel-to-reel media was used to preserve the data. These systems required magnetic tapes to be changed manually. It was a time consuming, expensive and unreliable process; the operator had to manually thread the tape from the tape reel through the recorder onto an empty take-up reel. Due to these short-comings, video surveillance was rare. Only when VCR technology became available in the 1970s, making it easier to record and erase information, did video surveillance start to become more common.[9]

During the 1990s, digital multiplexing was developed, which allowed several cameras to record at once, as well as time lapse and motion-only recording. This increased the use of CCTV[10] and increased the savings of time and money.

Recently CCTV has been transformed by the shift towards internet-based products and systems, and other technological developments.[citation needed]

Application[edit]

In September 1968, Olean, New York was the first city in the United States to install video cameras along its main business street in an effort to fight crime.[11] Another early appearance was in 1973 in Times Square in New York City.[12] The NYPD installed it in order to deter crime that was occurring in the area; however, crime rates did not appear to drop much due to the cameras.[12] Nevertheless, during the 1980s video surveillance began to spread across the country specifically targeting public areas.[10] It was seen as a cheaper way to deter crime compared to increasing the size of the police departments.[12] Some businesses as well, especially those that were prone to theft, began to use video surveillance.[12] From the mid-1990s on, police departments across the country installed an increasing number of cameras in various public spaces including housing projects, schools and public parks departments.[12] CCTV later became common in banks and stores to discourage theft, by recording evidence of criminal activity. In 1998, 3,000 CCTV systems were in use in New York City.[13]

Experiments in the UK during the 1970s and 1980s, including outdoor CCTV in Bournemouth in 1985, led to several larger trial programs later that decade. The first use by local government was in King's Lynn, Norfolk, in 1987.[14] 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 an increase in the number of CCTV systems installed. Today, systems cover most town and city centres, and many stations, car-parks and estates.

Uses[edit]

Crime prevention[edit]

The two year-old James Bulger being led away by his killers, recorded on shopping centre CCTV in 1993. This narrow-bandwidth television system had a low frame rate.

A 2009 analysis by Northeastern University and the University of Cambridge, "Public Area CCTV and Crime Prevention: An Updated Systematic Review and Meta-Analysis," examined 44 different studies that collectively surveyed areas from the United Kingdom to U.S. cities such as Cincinnati and New York.
The analysis found that:

  1. Surveillance systems were most effective in parking lots, where their use resulted in a 51% decrease in crime;
  2. Public transportation areas saw a 23% decrease in crimes;
  3. Systems in public settings were the least effective, with just a 7% decrease in crimes overall. When sorted by country, however, systems in the United Kingdom accounted for the majority of the decrease; the drop in other areas was insignificant.[15]

The results from the above 2009 "Public Area CCTV and Crime Prevention: An Updated Systematic Review and Meta-Analysis",[15][16] are somewhat controversial.[17] Earlier similar meta-analysis completed by Walsh and Farrington in 2002 showed similar results: a significant decrease in car park crime (41%), and a non-significant decrease of crime in public transit and public places.[18] This study was criticised for the inclusion of confounding variables (e.g. notification of CCTV cameras on site, improved street lighting) found in the studies analyzed (including car park studies). These factors could not be differentiated from the effect of CCTV cameras being present or absent while crimes were being committed.[16][17] Thus, a combination of factors might be important for the decrease in crime not just the CCTV cameras. The 2009 study admitted to similar problems as well as issues with the consistency of the percentage of area covered by CCTV cameras within the tested sites (e.g. car parks have more cameras per square inch than public transit).[16] There is still much research to be done to determine the effectiveness of CCTV cameras on crime prevention before any conclusions can be drawn.

Closed-circuit video cameras in the Navy Yard complex caught gunman Aaron Alexis during his shooting rampage.

There is strong anecdotal evidence that CCTV aids in detection and conviction of offenders; indeed UK police forces routinely seek CCTV recordings after crimes.[19] Moreover CCTV has played a crucial role in tracing the movements of suspects or victims and is widely regarded by antiterrorist officers as a fundamental tool in tracking terrorist suspects. Large-scale CCTV installations have played a key part of the defences against terrorism since the 1970s. Cameras have also been installed on public transport in the hope of deterring crime,[20][21] and in mobile police surveillance vehicles, often with automatic number plate recognition, and a network of APNI-linked cameras is used to manage London's congestion charging zone. Even so there is political hostility to surveillance and several commentators downplay the evidence of CCTV's effectiveness, especially in the US.[22] However, most of these assertions are based on poor methodology or imperfect comparisons.[23]

A more open question is whether most CCTV is cost-effective. While low-quality domestic kits are cheap the professional installation and maintenance of high definition CCTV is expensive.[24] Gill and Spriggs did a Cost-effectiveness analysis (CEA) of CCTV in crime prevention that showed little monetary saving with the installation of CCTV as most of the crimes prevented resulted in little monetary loss.[17] Critics however noted that benefits of non-monetary value cannot be captured in a traditional Cost Effectiveness Analysis and were omitted from their study.[17] A 2008 Report by UK Police Chiefs concluded that only 3% of crimes were solved by CCTV.[25] In London, a Metropolitan Police report showed that in 2008 only one crime was solved per 1000 cameras.[26] In some cases CCTV cameras have become a target of attacks themselves.[27]

Cities such as Manchester in the UK are using DVR-based technology to improve accessibility for crime prevention.[28]

In October 2009, an "Internet Eyes" website was announced which would pay members of the public to view CCTV camera images from their homes and report any crimes they witnessed. The site aimed to add "more eyes" to cameras which might be insufficiently monitored. Civil liberties campaigners criticized the idea as "a distasteful and a worrying development".[29]

In 2013 Oaxaca hired deaf police officers to lip read conversations to uncover criminal conspiracies.[30]

Industrial processes[edit]

Industrial processes that 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. Special cameras for some of these purposes include line-scan cameras and thermographic cameras which allow operators to measure the temperature of the processes. The usage of CCTV in such processes is sometimes required by law.[specify]

Traffic monitoring[edit]

Main article: Traffic camera

Many cities and motorway networks have extensive traffic-monitoring systems, using closed-circuit television to detect congestion and notice accidents.[31] Many of these cameras however, are owned by private companies and transmit data to drivers' GPS systems.

The UK Highways Agency has a publicly owned CCTV network of over 1,200 cameras covering the British motorway and trunk road network. These cameras are primarily used to monitor traffic conditions and are not used as speed cameras. With the addition of fixed cameras for the Active Traffic Management system, the number of cameras on the Highways Agency's CCTV network is likely to increase significantly over the next few years.[citation needed]

The London congestion charge is enforced by cameras positioned at the boundaries of and inside the congestion charge zone, which automatically read the licence 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.[citation needed]

Other surveillance cameras serve as traffic enforcement cameras.[citation needed]

Transport safety[edit]

Digital Video Recorder for Public Transport

A CCTV system may be installed where an operator of a machine cannot directly observe people who may be injured by some 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.[citation needed]

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.[citation needed]

Control of retail[edit]

Someas software integrate with CCTV to monitor the actions of workers in retail environments. Every action is recorded as an information block with subtitles that explain the performed operation. This helps to track the actions of workers, especially when they are making critical financial transactions, such as correcting or cancelling of a sale, withdrawing money or altering personal information.[citation needed]

Actions which an employer may wish to monitor could include:[citation needed]

  • Scanning of goods, selection of goods, introduction of price and quantity;
  • Input and output of operators in the system when entering passwords;
  • Deleting operations and modifying existing documents;
  • Implementation of certain operations, such as financial statements or operations with cash;
  • Moving goods, revaluation scrapping and counting;
  • Control in the kitchen of fast food restaurants;
  • Change of settings, reports and other official functions.

Each of these operations is transmitted with a description, allowing detailed monitoring of all actions of the operator. Some systems allow the user to search for a specific event by time of occurrence and text description, and perform statistical evaluation of operator behaviour. This allows the software to predict deviations from the standard workflow and record only anomalous behaviour.[citation needed]

Use in schools[edit]

In the United States, closed-circuit television is used for school security to monitor visitors, track unacceptable student behavior and maintain a record of evidence in the event of a crime. There are some restrictions on installation, cameras may not be used in an area where there is a "reasonable expectation of privacy". Examples of these are bathrooms, gym locker areas and private offices (unless consent by the office owner is given). Сameras are generally acceptable in hallways, parking lots, front offices where students, employees, and parents come and go, gymnasiums, cafeterias, supply rooms and classrooms. The use of cameras in classrooms is often debated by teachers who want cameras for protection and teachers who do not.[32]

Criminal use[edit]

Criminals may use surveillance cameras to monitor the public. For example, a hidden camera at an ATM can capture people's PINs as they are entered, without their knowledge. The devices are small enough not to be noticed, and are placed where they can monitor the keypad of the machine as people enter their PINs. Images may be transmitted wirelessly to the criminal.[33]

Prevalence[edit]

A crowdsourced map of CCTV cameras near Grande Arche using OpenStreetMap data.[34]
Surveillance camera mounted on the walls of Rosenbad, one of the Swedish's government buildings in central Stockholm, which houses the Prime Minister's office. One of the parliament's (Riksdagen) building can be seen in the background.
A surveillance camera, aimed at a public street (Kungsgatan) in Stockholm, Sweden, mounted on top of the pole.

With lower cost and easier installation, sales of home security cameras in the United States increased in the early 21st century.[35] Following the September 11 attacks, the use of video surveillance in public places became more common to deter future terrorist attacks.[12] In 2010, there were more than 10,000 CCTV systems in Chicago, many linked to an integrated camera network.[36]

In Latin America, the CCTV market is growing rapidly with the increase of property crime.[37]

An article published in CCTV Image magazine estimated the number of cameras in the United Kingdom was 1.85 million in 2011. The estimate was based on extrapolating from a comprehensive survey of public and private cameras within the Cheshire Constabulary jurisdiction.[38] This works out as an average of one camera for every 32 people in the UK, although the density of cameras varies greatly from place to place. The Cheshire report also claims that the average person on a typical day would be seen by 70 CCTV cameras.

The Cheshire figure is regarded as more dependable than a previous study by Michael McCahill and Clive Norris of UrbanEye published in 2002.[39] Based on a small sample in Putney High Street, McCahill and Norris estimated the number of surveillance cameras in private premises in London at around 500,000 and the total number of cameras in the UK at around 4,200,000. According to their estimate the UK has one camera for every 14 people. Although it has been acknowledged for several years that the methodology behind this figure is flawed,[40] it has been widely quoted.

The CCTV User Group estimated that were are around 1.5 million CCTV cameras in city centres, stations, airports, and major retail areas in the UK.[41] This figure does not include the smaller surveillance systems such as those that may be found in local corner shops and is therefore broadly in line with the Cheshire report.

Research conducted by the Scottish Centre for Crime and Justice Research and based on a survey of all Scottish local authorities, identified that there are over 2,200 public space CCTV cameras in Scotland.[42]

Privacy[edit]

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. Civil liberties campaign group Big Brother Watch have published several research papers into CCTV systems. In December 2009, they released a report documenting council controlled CCTV cameras.[43]

Proponents 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 weighed against the intended benefits of surveillance.[44] However, anti-surveillance activists have held that there is a right to privacy in public areas. Furthermore, while it is true that there may be scenarios wherein a citizen's right to public privacy can be both reasonably and justifiably compromised, some scholars have argued that such situations are so rare as to not sufficiently warrant the frequent compromising of public privacy rights that occurs in regions with widespread CCTV surveillance. For example, in her book Setting the Watch: Privacy and the Ethics of CCTV Surveillance, Beatrice von Silva-Tarouca Larsen argues that CCTV surveillance is ethically permissible only in "certain restrictively defined situations", such as when a specific location has a "comprehensively documented and significant criminal threat".[45] Her central reasoning is that widespread CCTV surveillance violates citizens' rights to privacy and anonymity within the public sphere by jeopardizing both their liberty and dignity. She concludes that CCTV surveillance should therefore be reserved for specific circumstances in which there are clear and reasonably demonstrated benefits to its implementation and few ethical compromises.

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. In 2004, the successor to the Data Protection Agency, the Information Commissioner's Office 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) limited the scope of the protection provided by this law, and not all CCTV systems are currently regulated.[46] However, private sector personnel in the UK who operate or monitor CCTV devices or systems are considered security guards and have been made subject to state licensing.

A 2007 report by the 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.[47][48] In the same year, the UK watchdog CameraWatch claimed that the majority of CCTV cameras in the UK are operated illegally or are in breach of privacy guidelines.[49] In response, the Information Commissioner's Office denied the claim adding that any reported abuses of the Data Protection Act are swiftly investigated.[49]

The UK Home Office published a code of practice in 2013 for the use of surveillance cameras by government and local authorities. The aim of the code is to help ensure their use is "characterised as surveillance by consent, and such consent on the part of the community must be informed consent and not assumed by a system operator. Surveillance by consent should be regarded as analogous to policing by consent."[50]

In Canada, the use of video surveillance has grown very rapidly. 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.[51]

Technological developments[edit]

Surveillance camera at London Heathrow Airport with a wiper for clear images during rain

Computer controlled analytics and identification[edit]

Computer controlled cameras can identify, track, and categorize objects in their field of view.[citation needed]

Video Content Analysis (VCA) is the capability of automatically analyzing video to detect and determine temporal events not based on a single image. As such, it can be seen as the automated equivalent of the biological visual cortex.

A system using VCA can recognize changes in the environment and even identify and compare objects in the database using size, speed, and sometimes colour. The camera’s actions can be programmed based on what it is “seeing”. For example; an alarm can be issued if an object has moved in a certain area, or if a painting is missing from a wall, or if a smoke or fire is detected, or if running people are detected, or if fallen people are detected and if someone has spray painted the lens, as well as video loss, lens cover, defocuss and other so called camera tampering events.[citation needed]

VCA analytics can also be used to detect unusual patterns in an environment. The system can be set to detect anomalies in a crowd, for instance a person moving in the opposite direction in airports where passengers are only supposed to walk in one direction out of a plane or in a subway where people are not supposed to exit through the entrances.[52]

VCA can track people on a map by calculating their position from the images. It is then possible to link many cameras and track a person through an entire building or area. This can allow a person to be followed without having to analyze many hours of film. Currently the cameras have difficulty identifying individuals from video alone, but if connected to a key-card system, identities can be established and displayed as a tag over their heads on the video.[citation needed]

There is also a significant difference in where the VCA technology is placed, either the data is being processed within the cameras (on the edge) or by a centralized server. Both technologies have their pros and cons.[53]

Facial recognition system Is a computer application for automatically identifying or verifying a person from a digital image or a video frame from a video source. One of the ways to do this is by comparing selected facial features from the image and a facial database.[citation needed]

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.[citation needed]

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.[citation needed] These systems do not observe people directly. Instead, they track their behavior by looking for particular types of body-movement behavior, or particular types of clothing or baggage.

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. Conservative critics fear the possibility that one would no longer have anonymity in public places. [54] 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.

Comparatively harmless are people counter systems. They use CCTV equipment as front end eyes of devices which perform shape recognition technology in order to identify objects as human beings and count people passing pre-defined areas.

Retention, storage and preservation[edit]

Most CCTV systems record and store digital video and images to a Digital Video Recorder or in the case of IP cameras directly to a server, either on-site or offsite.[citation needed]

The amount of data stored and the retention period of the video or pictures are subject to compression ratios, images stored per second, image size and duration of image retention before being overwritten.[55][56]

Recordings are usually kept for a preset amount of time and then automatically archived, overwritten or deleted. Videos are kept in order to allow retrieval and review in the event a crime was committed or the information needs to be studied for any number of reasons.[citation needed]

Many digital video recorders (DVR) for closed-circuit television (CCTV) store their contents in a proprietary file format, and export the video files to an optical storage media such as digital versatile disc. When the DVR is damaged before export, a proprietary format hinders recovery of video files and timestamps from a DVR hard disk in a forensically sound manner.

Closed-circuit digital photography (CCDP)[edit]

Closed-circuit digital photography (CCDP) is more suited for capturing and saving recorded high-resolution photographs, whereas closed-circuit television (CCTV) is more suitable for live-monitoring purposes.[citation needed]

However, an important feature of some CCTV systems is the ability to take high resolution images of the camera scene, e.g. on a time lapse or motion-detection basis. Images taken with a digital still camera often have higher resolution than those taken with some video cameras. Increasingly, low-cost high-resolution digital still cameras can also be used for CCTV purposes.[citation needed]

Images may be monitored remotely when the computer is connected to a network.[citation needed]

IP cameras[edit]

Main article: IP camera
Easy Connect Wireless IP camera

A growing branch in CCTV is internet protocol cameras (IP cameras). IP cameras use the Internet Protocol (IP) used by most Local Area Networks (LANs) to transmit video across data networks in digital form. IP can optionally be transmitted across the public internet, allowing users to view their cameras through any internet connection available through a computer or a 3G phone. For professional or public infrastructure security applications, IP video is restricted to within a private network or VPN,[57] or can be recorded onto a remote server.

Networking CCTV cameras[edit]

The city of Chicago operates a networked video surveillance system which combines CCTV video feeds of government agencies with those of the private sector, installed in city buses, businesses, public schools, subway stations, housing projects etc. Even home owners are able to contribute footage. It is estimated to incorporate the video feeds of a total of 15,000 cameras.[citation needed]

The system is used by Chicago's Office of Emergency Management in case of an emergency call: it detects the caller's location and instantly displays the real-time video feed of the nearest security camera to the operator, not requiring any user intervention. While the system is far too vast to allow complete real-time monitoring, it stores the video data for later usage in order to provide possible evidence in criminal cases.[58]

London also has a network of CCTV systems that allows multiple authorities to view and control CCTV cameras in real time. The system allows authorities including the Metropolitan Police Service, Transport for London and a number of London boroughs to share CCTV images between them. It uses a network protocol called Television Network Protocol to allow access to many more cameras than each individual system owner could afford to run and maintain.[citation needed]

The Glynn County Police Department uses a wireless mesh-networked system of portable battery-powered tripods for live megapixel video surveillance and central monitoring of tactical police situations. The systems can be used either on a stand-alone basis with secure communications to nearby police laptops, or within a larger mesh system with multiple tripods feeding video back to the command vehicle via wireless, and to police headquarters via 3G.[citation needed]

Integrated systems[edit]

An integrated systems unit.

Integrated systems allow users to connect remotely from the internet and view what their cameras are viewing remotely, similar to that of IP cameras. In one incident in 2009, a lady from Boynton Beach, Florida was able to watch her house get burgled and contacted police directly from her office at work.[59]

Wireless security cameras[edit]

Many consumers are turning to wireless security cameras for home surveillance.[citation needed] Wireless cameras do not require a video cable for video/audio transmission, simply a cable for power. Wireless cameras are also easy and inexpensive to install.[citation needed] Previous generations of wireless security cameras relied on analog technology; modern wireless cameras use digital technology which delivers crisper audio, sharper video, and a secure and interference-free signal.[60]

CCTV camera vandalism[edit]

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

  • Some people will deliberately destroy cameras. Some cameras can come with dust-tight, pressurized, explosion proof, and bullet-resistant housings.
  • Spraying substances over the lens can make the image too blurry to be read.
  • Lasers can blind or damage them. However, since most lasers are monochromatic, color filters can reduce the effect of laser pointers. However, filters will also impair image quality and overall light sensitivity of cameras (see laser safety article for details on issues with filters). Also, complete protection from infrared, red, green, blue and UV lasers would require use of completely black filters,[citation needed] rendering the camera useless.

See also[edit]

Notes[edit]

  1. ^ CCTV recording systems are still often used at modern launch sites to record the flight of the rockets, in order to find the possible causes of malfunctions,[5][6] while larger rockets often send pictures of stage separation back to earth by radio link.[7])

References[edit]

  1. ^ Verman, Romesh. Distance Education In Technological Age, Anmol Publications Pvt. Ltd., 2005, pp.166, ISBN 81-261-2210-2, ISBN 978-81-261-2210-3.
  2. ^ "Distance education in Asia and the Pacific: Proceedings Of The Regional Seminar On Distance Education, 26 November - 3 December 1986", Asian Development Bank, Bangkok, Thailand, Volume 2, 1987
  3. ^ "CCTV Digital Video Recorders (DVRs)". sourcesecurity.com. Retrieved 29 June 2013. 
  4. ^ Dornberger, Walter: V-2, Ballantine Books 1954, ASIN: B000P6L1ES, page 14.
  5. ^ "ET_SRB Cam FS.indd" (PDF). Retrieved 2009-07-22. 
  6. ^ "Ecliptic Enterprises Corporation". Eclipticenterprises.com. Archived from the original on July 5, 2008. Retrieved 2009-05-08. 
  7. ^ Brent D. Johnson. "Cameras Monitor Rocket Launch". Photonics.com. Retrieved 2009-05-08. 
  8. ^ "Television Rides Wires" , February 1949, Popular Science small article, bottom of page 179
  9. ^ CCTV Surveillance: Video Practices and Technology
  10. ^ a b [ Roberts, Lucy. “History of Video Surveillance and CCTV” We C U Surveillance http://www.wecusurveillance.com/cctvhistory Retrieved 2011-10-20]
  11. ^ [Robb, Gary C. (1979) "Police Use of CCTV Surveillance: Constitutional Implications and Proposed Regulations" University of Michigan Journal of Law Reform. pg. 572]
  12. ^ a b c d e f [Yesil, Bilge. (2006) “Watching Ourselves” Cultural Studies. Vol 20(4-5) pg. 400-416]
  13. ^ "You're being watched, New York!". BBC. 11 March 2002. 
  14. ^ Staff (August 2007). "CCTV". Borough Council of King's Lynn & West Norfolk. Retrieved 2008-12-14. 
  15. ^ a b "Public Area CCTV and Crime Prevention: An Updated Systematic Review and Meta-Analysis". Journalist's Resource.org. 
  16. ^ a b c Walsh B.C.,Farrington D.P. (2009). "Public area CCTV and crime prevention: An updated systematic review and meta-analysis". Justice Quarterly 26 (4): 716–745. doi:10.1080/07418820802506206. 
  17. ^ a b c d "Assessing the impact of CCTV" (PDF). Retrieved 2011-10-16. 
  18. ^ Walsh B.C.,Farrington D.P. (2009). "Effects of closed-circuit television on crime". The Annals of the American Academy of Political and Social Science 587 (1): 110–135. doi:10.1177/0002716202250802. 
  19. ^ "Police are failing to recover crucial CCTV footage, new figures suggest.," The Telegraph
  20. ^ "CCTV to drive down cab attacks," BBC
  21. ^ Taxi CCTV cameras are installed," BBC
  22. ^ Baram, Marcus (2007-07-09). "Eye on the City: Do Cameras Reduce Crime?". ABC News. Retrieved 2007-07-10. 
  23. ^ "Tens of thousands of CCTV cameras, yet 80% of crime unsolved" by Justin Davenport 2007
  24. ^ "National community Crime Prevention Programme" (PDF). Retrieved 2011-10-16. 
  25. ^ "Are CCTV cameras a waste of money in the fight against crime?" Forward Edge, 7 May 2008
  26. ^ Hughe, Mark (25 August 2009). "CCTV in the spotlight: one crime solved for every 1,000 cameras". Independent News and Media Limited. Retrieved 2009-08-27. 
  27. ^ "http://news.bbc.co.uk/," BBC
  28. ^ "Digital CCTV Scheme Switches On," BBC
  29. ^ Public to Monitor CCTV From Home, BBC
  30. ^ Angels of Silence see crime where others don't Globe & Mail, 20 Nov 2013
  31. ^ Motorway Cameras in England, http://www.motorwaycameras.co.uk[unreliable source?]
  32. ^ "Legal aspects of the use of video cameras in schools =". 
  33. ^ "ATM Security". Dedham Savings. Retrieved 2009-04-18. 
  34. ^ khris78. "The CCTV Map". osmcamera. Retrieved 2 August 2014. 
  35. ^ Home Security Camera Sales Rise cepro.com
  36. ^ "Chicago Links Police, Private Cameras". WLS-TV. 2010. Retrieved 2010-08-16. 
  37. ^ "Latin American Physical Security Market Growing Rapidly," 8 October 2009 Security Magazine
  38. ^ "Only 1.85 million cameras in UK, claims ACPO lead on CCTV - SecurityNewsDesk.com". SecurityNewsDesk.com. Retrieved 2011-03-02. 
  39. ^ "CCTV in London" (PDF). Retrieved 2009-07-22. 
  40. ^ "FactCheck: how many CCTV cameras? - Channel 4 News". Channel4.com. Retrieved 2009-05-08. 
  41. ^ "How many cameras are there?". CCTV User Group. 2008-06-18. Retrieved 2009-05-08. 
  42. ^ Bannister, J., Mackenzie, S. and Norris, P. Public Space CCTV in Scotland(2009), Scottish Centre for Crime and Justice Research (Research Report)
  43. ^ "Councils 'treble CCTV in decade'". BBC News. 2009-12-18. 
  44. ^ Smile, the cameras are here to watch over you - The New Zealand Herald, Tuesday 18 March 2008, Page A14
  45. ^ Von Silva-Tarouca Larsen, Beatrice (2011). Setting the watch: Privacy and the ethics of CCTV surveillance. Hart Publishing. p. 160. ISBN 978-1849460842. 
  46. ^ "Memorandum by A A Adams, BSc, MSc, PhD, LLM, MBCS, CITP School of Systems Engineering". UK Parliament Constitution Committee - Written Evidence. Surveillance: Citizens and the State. January 2007. 
  47. ^ "Privacy watchdog wants curbs on surveillance". The Telegraph. 1 May 2007. 
  48. ^ "CCTV, computers and the 'climate of fear'". Evening Standard. 30 April 2007. 
  49. ^ a b "Majority of UK's CCTV cameras 'are illegal'". The Telegraph. 31 May 2007. 
  50. ^ "Surveillance Camera Code of Practice". UK Government Home Office. June 2013. p. 5. Retrieved 1 December 2013. 
  51. ^ Freedom of Information and Protection of Privacy Act Text
  52. ^ "MATE's Analytics Integrate with Hirsch Security Systems". Retrieved 2011-03-28. 
  53. ^ "Image Processing Techniques for Video Content Extraction" (PDF). Retrieved 2011-03-28. 
  54. ^ Todd Lewan (July 7, 2007). "Microchips in humans spark privacy debate". USAToday. Retrieved 2012-06-07. 
  55. ^ "MotionJPEG, JPEG2000, H.264 and MPEG-4 compression methods in CCTV". Retrieved 2011-05-01. 
  56. ^ "H.264 compression versus MPEG4 compression for cctv video storage". Retrieved 2011-03-28. [unreliable source?]
  57. ^ "Some IP Cameras Can Be Remotely Monitored With An iPhone And Other Compatible 3G Devices" (PDF). Retrieved 2009-07-22. 
  58. ^ "Chicago's Camera Network Is Everywhere", The Wall Street Journal
  59. ^ Kim Segal (April 10, 2009). "Woman watches home invasion on webcam". CNN. Retrieved 2009-05-08. 
  60. ^ Digital Video Essentials: Shoot, Transfer, Edit, Share By Erica Sadun. Retrieved 16 October 2013. 

Further reading[edit]

External links[edit]