A webcam is a video camera that feeds its image in real time to a computer or computer network. Unlike an IP camera (which uses a direct connection using ethernet or Wi-Fi), a webcam is generally connected by a USB cable, FireWire cable, or similar cable.
Their most popular use is the establishment of video links, permitting computers to act as videophones or videoconference stations. The common use as a video camera for the World Wide Web gave the webcam its name. Other popular uses include security surveillance, computer vision, video broadcasting, and for recording social videos.
Webcams are known for their low manufacturing cost and flexibility, making them the lowest cost form of videotelephony. They have also become a source of security and privacy issues, as some built-in webcams can be remotely activated via spyware.
Early development 
First developed in 1991, a webcam was pointed at the Trojan Room coffee pot in the Cambridge University Computer Science Department. The camera was finally switched off on August 22, 2001. The final image captured by the camera can still be viewed at its homepage. The oldest webcam still operating is FogCam at San Francisco State University, which has been running continuously since 1994.
Connectix QuickCam 
The first commercial webcam, the black-and-white QuickCam, entered the marketplace in 1994, created by the U.S. computer company Connectix (which sold its product line to Logitech in 1998). QuickCam was available in August 1994 for the Apple Macintosh, connecting via a serial port, at a cost of $100. Jon Garber, the designer of the device, had wanted to call it the "Mac-camera", but was overruled by Connectix's marketing department; a version with a PC-compatible serial port and software for Microsoft Windows was launched in October 1995. The original QuickCam provided 320x240-pixel resolution with a grayscale depth of 16 shades at 60 frames per second, or 256 shades at 15 frames per second.
Later developments 
One of the most widely reported-on webcam sites was JenniCam, created in 1996, which allowed Internet users to observe the life of its namesake constantly, in the same vein as the reality TV series Big Brother, launched four years later. Other cameras are mounted overlooking bridges, public squares, and other public places, their output made available on a public web page in accordance with the original concept of a "webcam". Aggregator websites have also been created, providing thousands of live video streams or up-to-date still pictures, allowing users to find live video streams based on location or other criteria.
Around the turn of the 21st century, computer hardware manufacturers began building webcams directly into laptop and desktop screens, thus eliminating the need to use an external USB or Firewire camera. Gradually webcams came to be used more for telecommunications, or videotelephony, between two people, or among several people, than for offering a view on a Web page to an unknown public.
The term 'webcam' (a portmanteau) may also be used in its original sense of a video camera connected to the Web continuously for an indefinite time, rather than for a particular session, generally supplying a view for anyone who visits its web page over the Internet. Some of them, for example, those used as online traffic cameras, are expensive, rugged professional video cameras.
For less than US$100 in 2012, a Three-dimensional space webcam became available, producing videos and photos in 3D Anaglyph image with a resolution up to 1280 x 480 pixels. Both sender and receiver of the images must use 3D glasses to see the effect of three dimensional image.
Childcare webcast video monitoring 
Childcare webcams can offer improved security, communication, and increased service value in daycare facilities. According to researchers and industry leaders, as many as 100 childcare facilities add Internet viewing systems each month, and the total number of centers with some form of Internet monitoring runs into the thousands. In the United States, private services have been offering dedicated webcasting systems to centers nationwide for several years as of 2010.
Webcams have been increasingly used for Augmented Reality experiences online. One such function has the webcam act as a 'magic mirror' to allow an online shopper to view a virtual item on themselves. The Webcam Social Shopper is one example of software that utilizes the webcam in this manner.
Videocalling and videoconferencing 
As webcam capabilities have been added to instant messaging, text chat services such as AOL Instant Messenger, and VoIP services such as Skype, one-to-one live video communication over the Internet has now reached millions of mainstream PC users worldwide. Improved video quality has helped webcams encroach on traditional video conferencing systems. New features such as automatic lighting controls, real-time enhancements (retouching, wrinkle smoothing and vertical stretch), automatic face tracking and autofocus, assist users by providing substantial ease-of-use, further increasing the popularity of webcams.
Webcam features and performance can vary by program, computer operating system, and also by the computer's processor capabilities. Video calling support has also been added to several popular instant messaging programs.
Video security 
Webcams are also used as security cameras. Software is available to allow PC-connected cameras to watch for movement and sound, recording both when they are detected. These recordings can then be saved to the computer, e-mailed, or uploaded to the Internet. In one well-publicised case, a computer e-mailed images of the burglar during the theft of the computer, enabling the owner to give police a clear picture of the burglar's face even after the computer had been stolen.
Recently webcam privacy software has been introduced by such companies such as Stop Being Watched or Webcamlock. The software exposes access to a webcam and prompts the user to allow or deny access by showing what program is trying to access the webcam. Allowing the user to accept a trusted program the user recognizes or terminate the attempt immediately. Other companies on the market manufacture and sell sliding lens covers that allow users to retrofit the computer and close access to the camera lens.
Video clips and stills 
Webcams can be used to take video clips and still pictures. Various software tools in wide use can be employed for this, such as PicMaster (for use with Windows operating systems), Photo Booth (Mac), or Cheese (with Unix systems).
Input control devices 
Special software can use the video stream from a webcam to assist or enhance a user's control of applications and games. Video features, including faces, shapes, models and colors can be observed and tracked to produce a corresponding form of control. For example, the position of a single light source can be tracked and used to emulate a mouse pointer, a head mounted light would enable hands-free computing and would greatly improve computer accessibility. This can be applied to games, providing additional control, improved interactivity and immersiveness.
FreeTrack is a free webcam motion tracking application for Microsoft Windows that can track a special head mounted model in up to six degrees of freedom and output data to mouse, keyboard, joystick and FreeTrack-supported games By removing the IR filter of the webcam, IR LEDs can be used, which has the advantage of being invisible to the naked eye, removing a distraction from the user. TrackIR is a commercial version of this technology.
The EyeToy for the PlayStation 2, PlayStation Eye for the PlayStation 3, and the Xbox Live Vision camera and Kinect motion sensor for the Xbox 360 and are color digital cameras that have been used as control input devices by some games.
Small webcam-based PC games are available as either standalone executables or inside web browser windows using Adobe Flash.
Astro photography 
With the very low light capability, a few specific models of webcams are very popular to photograph the night sky by astronomers and astro photographers. Mostly, these are manual focus cameras and contain an old CCD panel instead of comparatively newer CMOS panels. The lens of the cameras are removed and then these are attached to telescopes to record images, video or still both. In newer techniques, videos of very faint objects are taken for a couple of seconds and then all the frames of the video are 'stacked' together to obtain a still image of respectable contrast. Philips PCVC 740K, and SPC 900 are one of the few webcams liked by astro photographers.
Webcams typically include a lens, an image sensor, support electronics, and may also include a microphone for sound. Various lenses are available, the most common in consumer-grade webcams being a plastic lens that can be screwed in and out to focus the camera. Fixed focus lenses, which have no provision for adjustment, are also available. As a camera system's depth of field is greater for small image formats and is greater for lenses with a large f-number (small aperture), the systems used in webcams have a sufficiently large depth of field that the use of a fixed focus lens does not impact image sharpness to a great extent.
Image sensors can be CMOS or CCD, the former being dominant for low-cost cameras, but CCD cameras do not necessarily outperform CMOS-based cameras in the low cost price range. Most consumer webcams are capable of providing VGA resolution video at a frame rate of 30 frames per second. Many newer devices can produce video in multi-megapixel resolutions, and a few can run at high frame rates such as the PlayStation Eye, which can produce 320×240 video at 120 frames per second.
Support electronics read the image from the sensor and transmit it to the host computer. The camera pictured to the right, for example, uses a Sonix SN9C101 to transmit its image over USB. Typically, each frame is transmitted uncompressed in RGB or YUV or compressed as JPEG. Some cameras, such as mobile phone cameras, use a CMOS sensor with supporting electronics "on die", i.e. the sensor and the support electronics are built on a single silicon chip to save space and manufacturing costs. Most webcams feature built-in microphones to make video calling and videoconferencing more convenient.
The USB video device class (UVC) specification allows for interconnectivity of webcams to computers without the need for proprietary device drivers. Microsoft Windows XP SP2, Linux and Mac OS X (since October 2005) have UVC support built in and do not require extra device drivers, although they are often installed to add additional features.
Many users do not wish the continuous exposure for which webcams were originally intended, but rather prefer privacy. Such privacy is lost when Trojan horse programs allow malicious hackers to activate the webcam without the user's knowledge, providing the hackers with a live video and audio feed. Cameras such as Apple's older external iSight cameras include lens covers to thwart this. Some webcams have built-in hardwired LED indicators that light up whenever the camera is active. It is not clear whether these indicators can be circumvented when webcams are surreptitiously activated without the user's knowledge or intent, via spyware.
In the field of computer security, camfecting is the fraudulent process of attempting to hack into a person's webcam and activate it without the webcam owner's permission. The remotely activated webcam can be used to watch anything within the webcam's field of vision, sometimes the webcam owner itself. Camfecting is most often carried out by infecting the victim's computer with a virus that can provide the hacker access to the victim's webcam. This attack is specifically targeted at the victim's webcam, and hence the name camfecting, a portmanteau of the words cam and infecting.
In mid-January 2005, some search engine queries were published in an on-line forum which allow anyone to find thousands of Panasonic- and Axis high-end web cameras, provided that they have a web-based interface for remote viewing. Many such cameras are running on default configuration, which does not require any password login or IP address verification, making them viewable by anyone.
Some laptop computers have built in webcams which present both privacy and security issues, as such cameras cannot normally be physically disabled if hijacked by a Trojan Horse program or other similar spyware programs. In the 2010 Robbins v. Lower Merion School District "WebcamGate" case, plaintiffs charged that two suburban Philadelphia high schools secretly spied on students - by surreptitiously remotely activating iSight webcams embedded in school-issued MacBook laptops the students were using at home — and thereby infringed on their privacy rights. School authorities admitted to secretly snapping over 66,000 photographs, including shots of students in the privacy of their bedrooms, including some with teenagers in various state of undress. The school board involved quickly disabled their laptop spyware program after parents filed lawsuits against the board and various individuals.
Effects on modern society 
Webcams allow for inexpensive, real-time video chat and webcasting, in both amateur and professional pursuits. They are frequently used in online dating and for online personal services offered mainly by women when Camgirling. YouTube is a popular website hosting many videos made using webcams. News websites such as the BBC produce professional live news videos.
Webcams can also encourage telecommuting, enabling people to work from home via the Internet, rather than traveling to their office.
The popularity of webcams among teenagers with Internet access has raised concern about the use of webcams for cyber-bullying. Webcam recordings of teenagers, including underage teenagers, are frequently posted on popular Web forums and imageboards such as 4chan.
Descriptive names and terminology 
Videophone calls (also: videocalls and video chat), differ from videoconferencing in that they expect to serve individuals, not groups. However that distinction has become increasingly blurred with technology improvements such as increased bandwidth and sophisticated software clients that can allow for multiple parties on a call. In general everyday usage the term videoconferencing is now frequently used instead of videocall for point-to-point calls between two units. Both videophone calls and videoconferencing are also now commonly referred to as a video link.
Webcams are popular, relatively low cost devices which can provide live video and audio streams via personal computers, and can be used with many software clients for both video calls and videoconferencing.
A videoconference system is generally higher cost than a videophone and deploys greater capabilities. A videoconference (also known as a videoteleconference) allows two or more locations to communicate via live, simultaneous two-way video and audio transmissions. This is often accomplished by the use of a multipoint control unit (a centralized distribution and call management system) or by a similar non-centralized multipoint capability embedded in each videoconferencing unit. Again, technology improvements have circumvented traditional definitions by allowing multiple party videoconferencing via web-based applications. A separate webpage article is devoted to videoconferencing.
A telepresence system is a high-end videoconferencing system and service usually employed by enterprise-level corporate offices. Telepresence conference rooms use state-of-the art room designs, video cameras, displays, sound-systems and processors, coupled with high-to-very-high capacity bandwidth transmissions.
Typical use of the various technologies described above include calling or conferencing on a one-on-one, one-to-many or many-to-many basis for personal, business, educational, deaf Video Relay Service and tele-medical, diagnostic and rehabilitative use or services. New services utilizing videocalling and videoconferencing, such as teachers and psychologists conducting online sessions, personal videocalls to inmates incarcerated in penitentiaries, and videoconferencing to resolve airline engineering issues at maintenance facilities, are being created or evolving on an on-going basis.
See also 
- Solomon Negash, Michael E. Whitman. Editors: Solomon Negash, Michael E. Whitman, Amy B. Woszczynski, Ken Hoganson, Herbert Mattord. Handbook of Distance Learning for Real-Time and Asynchronous Information Technology Education, Idea Group Inc (IGI), 2008, p. 17, ISBN 1-59904-964-3, ISBN 978-1-59904-964-9. Note costing: "students had the option to install a webcam on their end (a basic webcam costs about $40.00) to view the class in session."
- CoffeeCam, University of Cambridge.
- Spiegel CoffeeCam
- "Happy Birthday Fogcam" by Anjuli Elais in Golden Gate XPress, September 30, 2004
- Edwards, Benj. History of Video Calls: From Fantasy to Flops to Facetime, PC World Magazine, June 17, 2010.
- Ha, Peter. Computing: Connectix QuickCam, Time Magazine, October 25, 2010.
- "Plug pulled on live website seen by millions" by Oliver Burkeman in The Guardian, January 3, 2004
- Lanxon, Nate (2009-07-16). "3D photos: Minoru 3D webcam hands-on | CNET UK". Crave.cnet.co.uk. Retrieved 2013-01-07.
- "Augmented Reality Lets You Try On Clothes from Online Shops" TIME, 5 August 2011, retrieved 4 July 2012
- USB Camera with integrated UVC+UAC and Autofocus CMOS OV3640 CMOS Image sensor
- Serial burglar caught on webcam BBC News, February 16, 2005, retrieved January 3, 2006.
- Russia Election Webcams Wall Street Journal, January 16, 2012.
- Linux 2 6 26 – Linux Kernel Newbies
- Jogador esquece webcam ligada e transmite sexo com namorada, Yahoo!
- Gray, Leon (2009). Virtual crime! : solving cybercrime. Berkeley Heights, NJ: Enslow Publishers. ISBN 0766033767.
- "Google exposes web surveillance cams" by Kevin Poulsen, The Register, January 8, 2005, retrieved September 5, 2006
- Doug Stanglin (February 18, 2010). "School district accused of spying on kids via laptop webcams". USA Today. Retrieved February 19, 2010.
- "Initial LANrev System Findings", LMSD Redacted Forensic Analysis, L-3 Services – prepared for Ballard Spahr (LMSD's counsel), May 2010. Retrieved August 15, 2010.
- Holmes, Kristin E. (August 31, 2010). "Lower Merion School District ordered to pay plaintiff's lawyer $260,000". Philadelphia Inquirer. Retrieved September 20, 2010.
- ".". Main Line Media News. September 18, 2010. Retrieved September 20, 2010.
- Live radio studio webcams
- Poeter, Damon. "Webcam Peeper Convicted in Rutgers Cyberbullying Case," PC Magazine, March 16, 2012.
- Tip From 4chan Leads To Arrest Of Site Visitor On Child Porn Charges," The Smoking Gun, February 27, 2012.
- Goodin, Dan. Feds: bald man posing as 17-year-old secretly taped teens," The Register (UK), October 13, 2009.
- PC Magazine. Definition: Video Calling, PC Magazine website. Retrieved 19 August 2010,
- Mulbach, 1995. Pg. 291.
- Solomon Negash, Michael E. Whitman. Editors: Solomon Negash, Michael E. Whitman, Amy B. Woszczynski, Ken Hoganson, Herbert Mattord. Handbook of Distance Learning for Real-Time and Asynchronous Information Technology Education, Idea Group Inc (IGI), 2008, pg. 17, ISBN 1-59904-964-3, ISBN 978-1-59904-964-9. Note costing: "....students had the option to install a webcam on their end (a basic webcam costs about $40.00) to view the class in session."
- Lawson, Stephen. Vidyo Packages Conferencing For Campuses, IDG News Service, February 16, 2010. Retrieved via Computerworld.com's website, February 18, 2010
- Jackman, Elizabeth. New Video Conferencing System Streamlines Firefighter Training, Peoria Times, Peoria, AZ, February 19, 2010. Retrieved February 19, 2010;
- USA Today. "Video Chat Growing by Light-Year Leaps", USA Today, March 31, 2010, p. L01d.
- Mulbach, Lothar; Bocker, Martin; Prussog, Angela. "Telepresence in Videocommunications: A Study on Stereoscopy and Individual Eye Contact", Human Factors, June 1995, Vol.37, No.2, pg.290, ISSN 0018-7208, Gale Document Number: GALE|A18253819. Accessed December 23, 2011 via General Science eCollection (subscription).
Further reading 
|Wikimedia Commons has media related to: Webcams|
- Bajaj, Vikas. Transparent Government, Via Webcams in India, New York Times, July 18, 2011, pg.B3. Published online: July 17, 2011.