webcam is a video camera that feeds or streams imagery in real time to or through a computer to a computer network. When "captured" by the computer, the video stream can be stored, viewed or sent to another network through a system such as the Internet, and sent via email as an attachment. When sent to a remote location, the video stream can be saved, viewed or sent there. Unlike IP cameras (which connect using Ethernet or Wi-Fi), the webcam is generally connected by a USB cable, or a similar cable, or built into a computer hardware, such as a laptop.
The term "webcam" (truncated compound) can also be used in the original sense of a video camera connected to the Web continuously for an indefinite period, rather than for a particular session, generally providing a view for anyone visiting its web page. Through the internet. Some of them, for example, that are used as online traffic cameras, are expensive and rugged professional video cameras.
Video Webcam
Characteristics
Webcams are known for their low manufacturing costs and high flexibility, making them the lowest cost videotelephony form. Despite the low cost, the currently offered resolution (2015) is quite impressive, with a low-end webcam offering a resolution of 320ÃÆ'â € "240, a medium webcam that offers a resolution of 640ÃÆ' â €" 480, and an upscale webcam that offers 1280ÃÆ' â € " 720 (aka 720p) or even resolution 1920ÃÆ' â € "1080 (aka 1080p).
They are also a source of security and privacy issues, as some built-in webcam can be switched on remotely by spyware.
Maps Webcam
Usage
The most popular use of webcam is the establishment of video links, allowing computers to act as videophones or video conferencing stations. Other popular uses include security surveillance, computer vision, video broadcasting, and for recording social videos.
Video streaming provided by the webcam can be used for a number of purposes, each using the appropriate software:
Health care
Most modern webcam can capture arterial pulse by using simple algorithmic trick. Researchers claim that this method is accurate up to  ± 5 bpm.
Video monitoring
Webcams can be installed in places such as child care centers, offices, shops, and private areas to monitor security and general activities.
Trading
Webcams have been used for online augmented reality experiences. One such function has acted webcam as a "magic mirror" to allow online shoppers to see virtual stuff on themselves. Webcam Social Shopper is one example of software that uses a webcam in this way.
Videocalling and videoconferencing
Webcams can be added to instant messaging, text chat services such as AOL Instant Messenger, and VoIP services such as Skype, live one-to-one video communication over the Internet has now reached millions of mainstream PC users worldwide. Improved video quality has helped the webcam cruise through traditional video conferencing systems. New features like automatic lighting controls, real-time improvements (retouching, wrinkle and vertical stretching), automatic face tracking and auto-focus, help users by providing great usability, increasing the popularity of web cameras.
The features and performance of Webcam can vary based on program, computer operating system, and also computer processor capability. Video call support has also been added to some popular instant messaging programs.
Video security
Webcams can be used as security cameras. The software is available to allow the PC to connect the camera to watch gestures and sounds, recording both when they are detected. These recordings can then be saved to a computer, emailed, or uploaded to the Internet. In one well-publicized case, the computer sent a thieving image via email during computer theft, allowing its owner to give police a clear picture of the thief's face even after the computer was stolen.
Unauthorized access to a webcam can present significant privacy issues (see the "Privacy" section below).
In December 2011, Russia announced that 290,000 Webcams will be installed in 90,000 polling stations to monitor Russia's 2012 presidential election.
Video clips and stills
Webcam can be used to capture video clips and still images. Various widely used software can be used for this, such as PicMaster (for use with Windows operating systems), Photo Booth (Mac), or Cheese (with Unix systems). For a more complete list, see Comparison of webcam software.
Input control device
Custom software can use video streams from webcam to help or improve user control over apps and games. Video features, including faces, shapes, models, and colors can be observed and tracked to produce the appropriate form of control. For example, the position of a single light source can be traced and used to emulate a mouse pointer, headlamps will enable handheld computing and will greatly improve the accessibility of the computer. These can be applied to the game, provide additional control, increase interactivity and immersiveness.
FreeTrack is a free webcam motion tracking app for Microsoft Windows that can track special head-mount models in up to six degrees of freedom and output data to the mouse, keyboard, joystick, and FreeTrack supported games. By removing the IR webcam filter, IR LEDs can be used, which has the advantage of being invisible to the naked eye, eliminating interference from users. TrackIR is the commercial version of this technology.
The EyeToy for PlayStation 2, PlayStation Eye for PlayStation 3, and Xbox Live Vision cameras and Kinect motion sensors for Xbox 360 and color digital cameras that have been used as input control devices by multiple games.
Small webcam-based PC games are available either as a standalone executable or inside a web browser window using Adobe Flash.
Astro Photography
With very low light capabilities, some models of certain web cameras are very popular for photographing the night sky by astronomers and astro photographers. Mostly, this is a manual-focus camera and contains an old CCD array rather than a relatively new CMOS array. The camera lens is removed and then attached to the telescope to record images, videos, silence, or both. In newer techniques, a very dim video object is taken for a few seconds and then all the video frames are "stacked" together to get a still image with a respectable contrast.
Creation of laser light profile
The CCD webcam response is directly proportional to the incoming light. Therefore, the web camera is suitable for recording the laser light profile, once the lens is released. The resolution of the laser light profiler depends on the pixel size. Commercial webcams are usually designed to record color images. The size of the pixel color of the webcam depends on the model and may lie in the range of 5 to 10 Âμm. However, the color pixel consists of four black and white pixels each equipped with a color filter (for details see the Bayer filter). Although this color filter works well on the display, it may be somewhat transparent near infrared. By switching the webcam to Bayer mode, it is possible to access information from single pixels and resolutions below 3 m.
History
Initial development
First developed in 1991, a webcam was directed to a Trojan Space coffee pot at the Cambridge University Computer Science Department (originally operating through a local network instead of the web). The camera was finally turned off on August 22, 2001. The final image taken by the camera can still be seen on its homepage. In 2004, the oldest still operating webcam was FogCam at San Francisco State University, which has been ongoing since 1994.
Connectix QuickCam
The first commercial webcam, black and white QuickCam, entered the market in 1994, created by US computer company Connectix (who sold its product line to Logitech in 1998). QuickCam was available in August 1994 for Apple Macintosh, which was connected via serial port, costing $ 100. Jon Garber, the device designer, wanted to call it "Mac-camera", but was rejected by the Connectix marketing department; a version with a parallel port and PC-compatible software for Microsoft Windows was launched in October 1995. The original QuickCam provides 320x240-pixel resolution with 16 color grayscale depth at 60 frames per second, or 256 shadows at 15 frames per second. This cam was tested on several Delta II launches using various communication protocols including CDMA, TDMA, GSM and HF.
In 2010, Time magazine named QuickCam as one of the top computer devices of all time.
Videoconferencing through computers already exists, and when client-based videoconferencing software such as CU-SeeMe has started to become popular.
Next development
One of the most widely reported webcam sites is JenniCam, created in 1996, which allows Internet users to observe the lives of the namesake constantly, in the same vein as the reality TV series Big Brother, launched four years later. Other cameras are mounted facing bridges, public squares, and other public places, their output is available on public web pages according to the original concept of "webcam". The aggregator website has also been created, providing thousands of live video streams or the latest still images, allowing users to discover live video streams based on location or other criteria.
Around the turn of the 21st century, computer hardware manufacturers began building webcams directly onto laptop and desktop screens, thus eliminating the need to use an external USB or FireWire camera. Webcams have gradually begun to be used more for telecommunications, or videotelephony, between two people, or among several people, rather than offering unrecognized public Web page views.
Less than US $ 100 in 2012, a three-dimensional space webcam becomes available, producing videos and photos in anaglyph 3D images with resolutions up to 1280 ÃÆ'â € "480 pixels. Both the sender and the recipient of the image must use 3D glasses to see the effects of three-dimensional images.
Technology
Webcams usually include lenses, image sensors, support electronics, and may also include a microphone for sound. Various lenses are available, most commonly in consumer-grade webcam to be plastic lenses that can be screwed in and out to focus the camera. Fixed focus lens, which has no provision for adjustment, is also available. Due to the depth of field of camera systems larger for smaller and larger image formats for lenses with large f-number (small holes), the system used in webcam has a considerable depth of field so the use of fixed focus lenses does not affect the sharpness of the image for the most part.
Image sensors can be CMOS or CCD, formerly dominant for low-cost cameras, but CCD cameras do not always outperform CMOS-based cameras in low price range. Most consumer webcams are able to provide VGA resolution video with frame rate of 30 frames per second. Many newer devices can produce video in multi-megapixel resolution, and some can run at high frame rates like the PlayStation Eye, which can generate 320 Ã- 240 videos at 120 frames per second.
The electronic support reads the image from the sensor and sends it to the host computer. The camera pictured on the right, for example, uses Sonix SN9C101 to send the image via USB. Normally, each frame is transmitted uncompressed in RGB or YUV or compressed as JPEG. Some cameras, such as cell phone cameras, use CMOS sensors with "die" support electronics, ie sensors and supporting electronics built on a single silicon chip to save space and production costs. Most webcams come with an internal microphone to make video calls and video conferences even more convenient.
The USB video device specification (UVC) allows webcam interconnection to a computer without the need for proprietary device drivers. Microsoft Windows XP SP2, Linux and Mac OS X (since October 2005) have built-in UVC support and do not require additional device drivers, although they are often installed to add additional features.
Privacy
Many users do not want the continuous exposure that was originally meant for webcam, but prefer privacy. Such privacy disappears when malware allows malicious hackers to enable the webcam without the user's knowledge, providing hackers with live video and audio feeds. This is a special problem on many laptop computers, because such cameras can not usually be physically disabled if it is hijacked by Trojan Horse programs or other similar spyware programs.
Cameras like Apple's older external iSight camera include a lens cover to thwart it. Some webcams have an embedded LED indicator that turns on whenever the camera is on, sometimes only in video mode. However, it is possible for malware to evade the indicators and activate the camera clandestinely, as shown by researchers in the case of the built-in MacBook camera in 2013.
Various companies sell sliding lens cover and stickers that allow the user to retrofit a computer or smartphone to seal access to the camera lens as needed. One such company reported to have sold more than 250,000 of these items from 2013 to 2016. However, any blurry materials will work. Leading users include former FBI director James Comey.
The fraudulent process of trying to hack into someone's webcam and activating it without the owner's webcam permission has been called camfecting. Remotely-enabled webcams can be used to watch anything in the webcam vision field, sometimes the owner of the webcam itself. Camfecting is most often done by infecting victim's computer with a virus that can give hackers access to the victim's webcam. This attack is specifically targeted at the webcam of the victim, and hence the name camfecting , portmanteau of the words cam and infecting .
In January 2005, several search engine requests were published in online forums that let anyone find thousands of high-end Panasonic and Axis web cameras, provided they have a web-based interface for remote viewing. Many such cameras run on the default configuration, which does not require a password login or IP address verification, making it visible to anyone.
In the case of 2010 Robbins v. Lower Merion School District "WebcamGate", the plaintiff alleges that two suburban schools in Washington secretly spy on students - secretly activating the iSight Webcam installed on the MacBook laptops issued by the school students using at home - and thus violate their privacy rights. The school claimed to have secretly shot over 66,000 photos, including photographs of students in the privacy of their bedroom, including some with teens in various circumstances. School boards involved quickly disable their laptop spyware programs after parents file lawsuits against the board and various individuals.
Effects on modern society
Webcam allows to video and webcast chat in real-time, either amateur or professional. They are often used in online dating and for personal online services offered primarily by women while partying. However, the ease of using webcam over the internet for video chat has also caused problems. For example, the moderation system of various video chat sites like Omegle has been criticized as ineffective, with sexual content still rampant. In the case of 2013, the transmission of nude photos and videos via Omegle from a teenage girl to a school teacher resulted in the cost of child pornography.
YouTube is a popular website hosting many videos created using web cameras. News websites like the BBC also produce professional live news videos using web cameras rather than traditional cameras.
Webcams can also encourage telecommuting, allowing 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 concerns about the use of webcam for cyber-bullying. Adult webcam recordings, including underage teens, are often posted on Web forums and popular imageboard like 4chan.
Descriptive name and terminology
Videophone calls (also: videocalls and video chat ), are different from video conferences because they expect to serve individuals instead of groups. But the differences are becoming increasingly blurred with technological improvements such as increased bandwidth and sophisticated software clients that allow multiple parties to make calls. In general, the daily use of the term videoconferencing is now often used instead of videocall for point-to-point calls between two units. Videocone calls and videoconferences are also now commonly referred to as video links .
Popular webcams, relatively low cost devices that can provide live video and audio streams through personal computers, and can be used with many software clients for video calls and video conferencing.
Videoconferencing systems are generally more expensive than videophones and use larger capabilities. A video conferencing (also known as videoteleconference ) allows two or more locations to communicate via live and simultaneous video and audio transmissions. This is often achieved by using a multipoint control unit (centralized call distribution and management system) or with the same non-centralized multipoint capabilities implanted in each videoconferencing unit. Again, technological improvements have passed the traditional definition by allowing multi-party video conferencing via web-based applications. Separate web page articles are devoted to video conferencing.
Telepresence systems are high-tech videoconferencing systems and services that are typically used by enterprise-level corporate offices. Telepresence conference rooms use the design of art space, video camera, display, sound-system and processor, coupled with high-capacity high bandwidth transmission.
Common uses of the various technologies described above include one-on-one, one-to-many or many-to-many calls or conferences for Personal, business, education, hearing-impaired and tele-medical, diagnostic and use services or rehabilitation services. The new services utilize videocalling and videoconferencing, such as teachers and psychologists who conduct online sessions, private videocalls for prisoners imprisoned in prisons, and video conferencing to solve airline engineering problems at maintenance facilities, are being created or growing sustainably.
See also
- Action camera
- Rewrite
- Camgirling
- Webcam software comparison
- Document camera
- IP camera
- iSight
- List of webcameras and videophone
- Optical Nerve (GCHQ)
- Camera zoom pan slope
- QuickCam
- Trail Camera - A special outdoor Digital Camera that operates on battery and saves detected images to SDCARD
References
Bibliography
- Mulbach, Lothar; Bocker, Martin; Prussog, Angela. "Telepresence in Video Communication: Study of Stereoscopy and Individual Eye Contact", Human Factors , June 1995, Vol.37, No.2, p.290, ISSNÃ, 0018-7208, Gale Document Number: GALE | A18253819. Retrieved 23 December 2011 via General Science eCollection (subscription).
Further reading
- Bajaj, Vikas. Transparent Government, Via Webcam in India, The New York Times , July 18, 2011, p.B3. Published online: July 17, 2011.
Source of the article : Wikipedia
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