What are webcams? Webcam: what is it and what is it for? What is a computer web camera

A webcam is a digital camera connected to a computer. The device is designed for scanning, processing and transmitting images via the Internet in real time. Most often used for online broadcasts and making video calls.

Historical coffee stream

The first webcam was the invention of Cambridge geniuses Quentin Stafford-Fraser and Paul Jardetsky. The device appeared in 1991 thanks to the love of university staff for coffee. At that time, there was only one coffee pot in the Trojan Room for the entire computer development department. Often scientists had to travel a long way to get a glass of this wonderful drink in vain. So that everyone can see whether the coffee is ready without leaving their workplace, a web camera was created.

Initially, the image was broadcast only to the department’s working computers via a local network and was 128x128 pixels in size. The development received the client name XCoffee for Window System. The online broadcast lasted 10 years. In 2001, despite protests from fans, the camera was turned off. The coffee pot became a famous rarity and was sold on eBay for £3,350.

The device of a modern webcam

The main part of a webcam is the image sensor, or CCD matrix. It is a semiconductor chip consisting of millions of tiny light-sensitive squares arranged in a grid. These squares are called pixels. Basic webcams use relatively small sensors, only a few hundred thousand pixels.

In addition to the CCD or ROM sensor, the camera contains a lens, an analog-to-digital converter, also called a video capture card, a microprocessor and a compressor. Some IP camera models contain a built-in web server and RAM.

How a webcam works

A standard webcam is a separate device connected to a computer. It works as follows:

1. Through a lens on the front, the camera captures light and projects it onto an integrated circuit made of microscopic light detectors.
2. The video capture card converts the analog image into a digital image, that is, into a bytecode of zeros and ones.
3. Compression blocks compress a digital signal into MJPEG or MPEG formats.
4. Then the information is transferred to the computer via a USB interface, and then to the Internet.

In cases with IP cameras, connecting to a computer is not necessary. The device has its own IP address thanks to the built-in web server, and streaming is carried out directly to the network.

Webcam settings

If you take two webcams apart, you get an identical set of parts: a board with a photosensitive matrix and a lens. How do you know which works well and which doesn’t?

1. Resolution - the number of pixels vertically and horizontally of the matrix. The more there are, the better and more expensive the device is. Modern HD webcams transmit images in real time with a resolution between 1280×720 and 1600×1200, that is, 3-2.0Mpx. For budget models this parameter is 320x240 or 640x480. The picture turns out grainy, sometimes blurry. But not every Internet connection will support a 2.0Mpx camera. If the data transfer speed is low, up to 10-20 MB, the image will freeze.
2. FPS is the number of frames per second that the camera is capable of processing. Inexpensive models have a frame rate of about 24 frames per second, while for PRO cameras this value reaches 50-60. Mid-range cameras, such as the Microsoft VX-1000 or VS-800, have a frame rate of 30 frames per second with a resolution of 640x480. If you sit still during a video chat, then even with low fps the image will be quite clear. But for shooting in motion, the frequency must be above 40 frames per second.

These are two key parameters that determine the level of the webcam. There are additional options that have almost no effect on the quality of the device and image. Basically they affect the price, and not always justifiably.

What is a webcam for?

The purpose of a webcam is to show objects that are out of sight and reach. With its help, you can remotely monitor people and premises in real time. For example, if you are going to another city or to the sea, the webcam will show the weather better than any weather forecaster.

90% of users purchase a gadget for video calls, chats and video conferencing via the Internet. To do this, you must have special software installed on your computer that supports VoIP: Skype, ooVoo or Viber. Instead of client programs, you can use Appear.in or Hangouts browser extensions. But the range of camera capabilities doesn’t end with video chats:

1. Online broadcasts of what is happening in the most popular corners of the earth. Webcams in Sochi, New York and near Niagara Falls allow you to travel without leaving your computer chair.
2. Security companies and security services widely use this technology to monitor objects.
3. Video from a webcam can be recorded, edited, posted on the Internet, on forums, in a playlist on YouTube or on a blog. There are a lot of programs for these purposes, some of which are Windows Movie Maker or Camtasia Studio.
4. Using web applications, create emails in video format.
5. Conduct paid training webinars and earn money using the gadget.

Unconventional Ways to Use a Webcam

Broadcasts from webcams on the sea, embankments, and from an eagle’s nest in the Himalayas will no longer surprise anyone. But there are some unusual and fun ways to use the gadget:

1. OvO Webcam Games or GloopIt Webcam Utility. Participants control their characters via webcam. For such entertainment, you need to point the monitor at yourself and complete quests with the movements of all parts of your body. Gaming software is downloaded from the Internet and installed on the computer.
2. Using gesture recognition technology, control desktop software, YouTube, Pandora, Grooveshark and Netflix players in the Chrome browser. The mouse and keyboard are not used, only the movement of the hands. The development is called Flutter and is currently in alpha testing.
3. Create animated GIFs and avatars using WebCam Avatar or PsykoGif.
4. Use to log into your account without entering a password.

From a webcam with a built-in microphone, a PC and Skype, every attentive parent can install a video nanny. To do this, you need to create a new account in the messenger in the child’s name, add yourself and your relatives to the contact list. Set up Skype to automatically answer video calls and turn on the camera. The computer with the gadget must be installed so that the entire nursery is visible, including the child himself. With this know-how, you can monitor your child at any time.

What is a webcam and why is it needed?

Webcam (Webcam, web camera) - a digital camera capable of taking pictures in real time for further transmission over the Internet.

Webcams transmit images to a web server either on demand, continuously, or at regular intervals.

This is achieved either by connecting the webcam to the computer, or using the webcam itself.

Many modern webcams are equipped with hardware and software that allows it to independently work as a web server, FTP server, FTP client and/or transmit information by e-mail.

Webcams for video conferencing- a type of webcam connected to a computer running a video conferencing program.

Security web cameras- digital video cameras installed both outside and indoors. They can be equipped with various additional functions (motion detectors, temperature, humidity sensors, etc.). Images from security web cameras can be transmitted over the Internet and received, for example, on mobile devices.

Webcams are popular in all civilized countries of the world. On the Internet you can find millions of webcams broadcasting almost anything. You can find webcams broadcasting the life of rabbits in an enclosure, aquarium fish, street views, etc.

If you install a webcam indoors, you can use it at any time, for example, to advertise goods and services.

A webcam installed inside the store allows you to conduct an interactive dialogue with potential customers.

Webcams actually allow you to create continuous videos. For those who do not know how or are afraid to shoot video on their own, webcams are a good solution to this problem.

Did you know?

The first webcam is believed to have been launched in 1991 and showed a coffee maker in the Trojan Room at Cambridge University. The webcam was disabled on August 22, 2001.

Note for Muscovites

Installation of external technical means (antennas, web cameras, video cameras, air conditioners, etc.) must be carried out according to a project agreed upon with the Main APU of the Moskomarkhitektura and the Moszhilinspektsiya.

According to Russian laws, video surveillance in public places must be obvious; hidden video surveillance cameras can only be installed by court order .

Violating the law when installing video surveillance will not give you the opportunity to use the video material in court, because a video recording of any offense will be considered made illegally and will have no legal force.

For reference

Article 24 of the Constitution of the Russian Federation
1. Collection, storage, use and dissemination of information about the private life of a person without his consent is not permitted.
Article 137. Criminal Code of the Russian Federation. Violation of privacy
1. Illegal collection or dissemination of information about the private life of a person, constituting his personal or family secret, without his consent, or dissemination of this information in a public speech, publicly displayed work or the media - is punishable by a fine of up to two hundred thousand rubles or in the amount of wages wages or other income of the convicted person for a period of up to eighteen months, or compulsory work for a period of one hundred twenty to one hundred and eighty hours, or correctional labor for a period of up to one year, or arrest for a period of up to four months.

For installation of technical means(antennas, web cameras, video cameras, air conditioners, etc.) inside the apartmentthe owner does not require permission.

Note:

You can use a mobile phone, digital camera, or digital video camera as a webcam.

The webcam can be installed inside an office, store, car service center, etc. You do not need to obtain any permissions for this.

Services for creating highly efficient and competitive turnkey multimedia websites using simple and reliable software and hardware are provided by the Antula web studio.

I present to your attention an article about webcams. This device, of course, is not new in the modern world for a long time, and many people use this wonderful device, thanks to which you can not only see the person you are interested in on the other side of the world, but also watch any corner of our planet where a webcam is located. But first things first. So…

Webcam , or Webcam , or Web camera (English) Webcam ) - a small-sized digital video or photo camera capable of recording images in real time, intended for further transmission over the Internet (in programs such as Skype, Instant Messenger or in any other video application that allows you to support video communication). Recently, you can even communicate using a webcam on some social networks, for example Odnoklassniki.

Webcam history

It all started in one of the computer laboratories in Cambridge back in the early 90s of the last century, when the Global Wide Web (Internet) was just beginning its victorious march across the planet.

A group of scientists, about 15-20 people, worked on a project in the field of network technologies. The working conditions were spartan - there was only one coffee maker for the entire team, which could not meet the needs of the entire team. The main work was carried out in the laboratory; the staff lived in the same building, but in a different part of it. To spur their thinking process with a cup of invigorating drink, participants in the scientific project were forced to frequently visit the corridor located on the floor above, where the coffee maker was located. Often such trips failed, since some colleagues had already managed to empty the coveted container. The situation required a non-standard solution, and it was found.

One of the computers in the laboratory had a video surveillance device (frame grabber). A camera was connected to it, which was aimed at the object of observation. The same computer played the role of a web server using specially written software. Those who wanted to know whether there was coffee had to run client software on their computer that connected to the server. As a result, a black and white image was displayed on the remote computer in a small window, updated three times a minute. A note about this interesting complex was published in Comm-Week magazine on January 27, 1992.

Not much time has passed since the appearance of the first prototypes of IP cameras, but they have already turned into a fully formed, separate class of devices that make everyday life easier, more convenient and more fun.

The light sensor is kind of the heart of any digital camera. It is this that makes it possible to convert light into electrical signals available for further electronic processing.

The basic principle of operation of both CCD and CMOS sensors is the same: under the influence of light, charge carriers are created in semiconductor materials, which are subsequently converted into voltage.

The difference between CCD and CMOS sensors lies primarily in the method of accumulating and transferring charge, as well as in the technology for converting it into analog voltage. Without going into details of the design of various types of sensors, we will only note that CMOS sensors are much cheaper to produce, but also noisier.

The principle of operation of a Web camera is similar to the principle of operation of any or. In addition to the optical lens and the photosensitive CCD or CMOS sensor, the presence of an analog-to-digital converter (ADC) is required, the main purpose of which is to convert the analog signals of the photosensitive sensor, that is, voltage into a digital code. In addition, a color formation system is required. Another important element of the camera is the circuit responsible for compressing data and preparing it for transmission in the required format. In Web cameras, video data is transferred to the computer via a USB interface, that is, the final circuit of the camera must be a USB interface controller.

An analog-to-digital converter deals with sampling a continuous analog signal. Such converters are characterized both by the sampling frequency, which determines the time intervals through which the analog signal is measured, and by their bit capacity. The ADC width is the number of bits used to represent the signal. For example, if an 8-bit ADC is used, then there are 8 bits to represent the signal, which allow 256 different values ​​to be specified. When using a 10-bit ADC, it is possible to discretely set 1024 different signal levels.

Given the low bandwidth of the USB bus (only 12 Mbit/s, of which the Web camera uses no more than 8 Mbit/s), the data must be compressed before direct transmission to the computer. The obviousness of this follows from a simple calculation. With a frame resolution of 320x240 pixels and a color depth of 24 bits, the uncompressed frame size will be 1.76 Mbit. With a USB channel bandwidth of 8 Mbit/s, uncompressed frames can be transmitted at a speed of no more than 4.5 frames/s. However, to obtain high-quality video, a bit rate of 24 fps or more is required. Thus, it becomes clear that without hardware compression of the transmitted information, the operation of the camera would be impossible. Therefore, any camera controller must provide the necessary data compression for transferring it via the USB interface. Compression itself is the main purpose of the USB controller. Providing the necessary compression in real time, the controller, as a rule, allows you to transmit a video stream at a speed of 10-15 frames/s at a resolution of 640x480 and at a speed of 30 frames/s at a resolution of 320x240 and lower.

Amateur webcams. This type of webcam is intended mainly for video communication, video conferencing, video recording and photography. These cameras are relatively inexpensive and easy to use. We will introduce you to the detailed characteristics of amateur webcams a little later.

Professional webcams(Network webcams or IP cameras). This type of webcam is used mainly for video surveillance of protected objects, or for other similar purposes. A modern IP camera is a digital device that captures video, digitizes, compresses and transmits video images over a computer network. Unlike a regular webcam, a network camera functions as a web server and has its own IP address. Thus, it is possible to directly connect the camera to the Internet, without a computer, which allows you to receive video and audio signals and control the camera via the Internet through a browser.

Now we have learned, dear readers, what a webcam is, its operating principle, history, types. Let's move on to the question of choosing a webcam. So, what should you pay attention to when buying a webcam?

Sensor Type

You need to pay attention to this parameter first of all if you are choosing a non-budget webcam, for example for commercial purposes. This is due to the fact that basically all amateur webcams have one of two main types of matrices - CMOS. This matrix is ​​not expensive to manufacture, has low power consumption, and has the basic necessary technical characteristics for comfortable use of the webcam.

Another type of matrix is ​​CCD. It has improved video quality characteristics, and accordingly, CCD webcams have a higher price.

As for me, you can take a CMOS camera and enjoy life without overpaying an extra hundred or two dollars. Although, if you have nowhere to put them, then go ahead!

Frame per second (Fps)

This parameter actually directly affects the smoothness of the image transmitted by the webcam. The more frames per second the webcam transmits, the less upset you will be in video communication with your opponent.

Webcams are found with 8, 15, 30 frames per second or more. The optimal rate is 30 frames per second.

Important! The more frames per second a video signal has, the larger its size, and accordingly, for normal video communication, higher-speed Internet is required.

Picture resolution

For video, resolution ranges from 0.1 to 2 megapixels. It is worth noting that the optimal, and at the same time the most popular, is the VGA format (640x480 pixels, 0.3 MP). These are the cameras that are recommended for purchase for regular, home Internet communication.

A resolution of 320×240 (0.1 megapixel) will be quite sufficient, for example, for Internet video conferencing, and this figure should be increased when the ability to view the interlocutor in high quality is of paramount importance.

Important! The higher the resolution of the video signal, the larger its size, and accordingly, for normal video communication, higher-speed Internet is required.

I would like to note that at the moment, the Internet has increasingly high connection speeds, and accordingly, webcams with Full HD 1080p resolution (1920×1080) have appeared, which allows you to view high-definition video signals in high definition and excellent quality.

To be honest, due to technological progress, they may suggest that in a year or two there will be webcams with the ability to record video in 3D. Although, perhaps this already exists now, and I just lost sight of this new product somewhere.

Optics

There are webcams with plastic and glass lenses.

Budget amateur webcams mostly have plastic optics, which accordingly does not always transmit the image in natural colors.

Glass optics have more natural color rendering. I’m not sure that all salespeople in stores know about this parameter, but if you like the maximum in everything, pay attention to the optics of the webcam.

I saw on sale a webcam with Carl Zeiss optics, which is used in cameras and video cameras by Sony.

Matrix sensitivity

An important parameter that determines the minimum degree of illumination of an object at which the webcam is capable of taking pictures of acceptable quality. The sensitivity of the webcam matrix is ​​measured in lux.

Important! In low light conditions, even an expensive webcam with a CCD matrix produces a noisy picture.

Microphone

I decided to mention it because... I was recently looking for an inexpensive webcam, and I couldn’t even imagine that they still exist without built-in microphones. To be honest, it’s not very convenient to use a microphone if you can communicate without headphones with a microphone. And so, you connect one device, and you speak to yourself without tying yourself up with unnecessary cords :)

One more nuance. The microphone can be connected either through the same USB connector through which the webcam itself is connected, or through a parallel microphone plug. It is convenient when the entire device operates via one cable, without additional plugs.

By the way, sound recording can be recorded in either mono or stereo mode. The choice is yours.

Fastening

Please pay attention to this little detail. The fact is that there are webcams that, after purchase, you have to tape to the monitor or somewhere else with tape, insert all sorts of pieces of paper, rubber bands, etc. If possible, ask the seller to demonstrate the webcam mount. Try attaching it to something yourself on the spot.

Focusing

The clarity of the transmitted image depends on the focusing.

Webcams come with both manual and automatic focusing. It’s convenient to have both in one device. Why? You will learn about this when you start using the webcam.

Photo opportunity

Most types of webcams have a photo function. There is a button on the webcam body that, when pressed, takes a photo. I’ll say right away that the quality is worse than on a camera, so don’t count on it too much. But for an avatar photo, that’s it. Although some say that a photo with a large number of megapixels becomes beautiful.

If you are interested in finding out what affects the quality of a photograph in a camera, read.

Connection type

Basically, all webcams are connected using a USB connector.

This connector has 3 standards: USB 1.1, USB 2.0, USB 3.0.

For a regular webcam, USB 2.0 is the optimal setting. If you purchase a device with the ability to transmit video in Full HD 1080p resolution, then it is advisable that the camera has a USB 3.0 connector. Although manufacturers are trying to do everything optimally, as the saying goes: “It’s better to be safe than sorry.”

Also, as I mentioned above, please note that a camera with a built-in microphone does not have an additional plug to connect it.

There are also webcams, mostly professional ones, with the ability to transmit video signals via a wireless Wi-Fi channel. Very comfortably.

Additional webcam features

A webcam can have a number of additional functions: functions for editing information, controlling brightness and contrast, color correction, frame rate, and password protection.

A professional webcam can be equipped with a motion detector and have a rotating mechanism, which allows it to be used for video surveillance.

Brand

I am used to paying attention to the manufacturer almost always, especially when it comes to electronics.

Firstly, this is the quality and warranty on the device itself. After all, if something happens, when looking for a service center, you don’t want to discover that it, as such, does not exist in the country in which you live, because... it is only available in China, where the lion's share of electronics is produced.

Secondly, it is your safety and that of your loved ones. Now there are news when even a doll in the hands of a child explodes, let alone more complex technology.

Who knows who and where they were thinking when they created a fake of this or that device.

The most popular webcam brands: Logitech, Creative, A4 Tech, Genius, Sven, Microsoft, Trust, Canyon.

I would buy Logitech for myself. May the competitors of this brand forgive me :-).

Important! I ask you, dear readers, do not purchase webcams from suspicious places that sell electronics, for example, at the car market. Thank you

The cheapest webcam, with a minimum set of functions, can be purchased for 8 USD.

A standard webcam with a built-in microphone and a resolution of 640x480 can be purchased for about 20 USD.

A webcam with all the bells and whistles can be purchased for about 120 USD.

Video: How to choose a webcam

A professional webcam is a digital video or photo camera that allows you to scan the image around the webcam in real time and transmit this image over the Internet. To transfer images over the Internet, use the Instant Messenger program or another program that allows you to play back the image transmitted to the camcorder.

What does a webcam consist of?

Any web camera consists of a video camera (CCD matrix), a special compression processor, and a built-in web server. Today, there are two types of matrices: CCD matrices and CMOS matrices. Such matrices differ in the degree of detail and image clarity. During operation, the web camera shoots video and converts the analog signal into a digital signal. The converted digital signal is processed by a special video capture card. After this, the video image can be transmitted over the Internet.

Structurally, the video camera includes: a CCD matrix, an optical filter and a lens, a special computer video capture card, a video compression unit, RAM and a central processor, flash memory and a network interface, ports for connecting to various devices.

The CCD matrix is ​​a light-sensitive conductor. A conductor is a plate that converts light into an electrical impulse. The CCD matrix includes a significant number of photosensitive cells. That is why the sensitivity of the CCD matrix directly depends on the number of effective pixels.

insides of a webcam with and without lens

A web camera lens is used to project an image of an object onto a computer's CCD matrix. The quality of the image formed largely depends on the quality of the lens. Some of the key characteristics of the lens are: focal length, depth of field of the lens, format and other technical characteristics of the web camera.

Optical filters of a web camera have the form of flat parallel plates. Such plates are located on top of the matrix and are designed for high-quality color rendering of the web camera.

The web camera video capture card converts the analog electrical signal into digital format.

The web camera compression unit compresses video signals. By reducing its volume, it converts video signals into compression formats such as JPEG, MJPEG, MPEG - 1/2/4 or Wavelet. Video signal compression allows you to significantly reduce the amount of video information for easy storage and transportation of video images over the Internet. There are hardware and software video compression. Most webcams are released with hardware compression, as this is the fastest compression method.

With the help of the central processor, tasks of reproducing compressed and digitized video images are carried out. Interface – Ethernet is responsible for connecting the webcam to the local network. If there is a USB port (the more common type), the camera can be connected directly to the computer input.

Optionally, the webcam may contain web server software. Then it becomes a completely autonomous service, the connection to which can be made directly by users via the Internet. In the usual case, the camera is used as a generator of a video stream, which is processed by a computer and transmitted to the network using software installed on it.

Advantages and disadvantages of a web camera

The main advantage of a web camera is its mobility and the ability to transmit video information online. The disadvantage of the web camera is the rather low image quality and the mandatory presence of a broadband Internet connection to transmit the image online. For normal image recording, broadband Internet access is not required.

How does a webcam work?

After connecting the webcam to the Internet, it is assigned a web address. There are also special programs that automatically assign an address to a web camera. When a web camera is detected by a computer, it begins to work as a network device, converting the image entering the lens into a digital signal for recording or transmission to the Internet. This is how the web camera works.

Hello everyone! In today's article we will talk about the security of Webcams. We have already talked in detail about all the methods. If you haven't read it yet, I encourage you to read it.

Today, in follow-up to that article, I decided to write about how to find out which program uses the Webcam. This may be useful in some cases. And not only in situations related to viruses and malware, but also in case of device conflicts in the operating system. For example, quite often such conflicts occur when using Skype.

In Windows 10, you control how apps use your webcam using a native feature. It is located in the “Settings” -> “Privacy” -> “Camera” section.

This is a pretty useful thing for controlling application access to the webcam. If you use Windows 10, then in terms of security, I highly recommend disabling everything unnecessary that can use the webcam.

If you are not using the webcam at all, then move the “Allow applications to use...” slider to the off position. If you intend to use the webcam with certain applications, then you should disable only unnecessary applications.

All this is of course good. But there is one thing... You understand that not a single normal malicious one will be visible on this list. Such programs are good at camouflaging themselves and hiding their presence in the system.

What to do in such a situation? How to determine which program is using the Webcam?

Very simple. We will search for a webcam in running processes by the physical name of the device using the small and free program Process Explorer from Microsoft. This utility will greatly simplify and speed up the search for a device. The presented method works on Windows 10, 8, 8.1, 7 operating systems.

So friends, let's move on to the instructions themselves.

What program uses the Webcam

Let's launch Device Manager. To do this, use the Win + R key combination to open the “Run” window.

In which you need to enter the command “devmgmt.msc” and click “Ok”.

After that, in the “Task Manager” window that appears, in the “Image processing devices” drop-down menu, we will find the webcam. If you have several webcams installed on your system, follow these steps for all of them.

Double clicking on the device will open the settings window. By default, the General tab will open, but we want the Details tab.

On the “Details” tab, in the “Properties” drop-down menu, find the item “Physical object name...”. And in the “Value” field, right-click its name.

Now you need to download the small free application Process Explorer. By the way, a very useful program. It may be useful to you in different situations. I recommend mastering it. In many of our instructions we will use it or other similar programs that replace the standard Windows task manager.

After installation, run the program and use the Ctrl+F key combination to open the search, in which we will paste the device name copied to the clipboard. Click on the search button and wait for the process to complete.

If after the end of the search no results are found, then this can only indicate that the webcam is not being used by any application at that particular moment.

But there may be a different picture. As you can see from the screen above, in my case the webcam is occupied by the Google Chrome browser.

What could this mean?

The first is that one of the open sites is currently using a webcam. Typically, to enable the user's Webcam, the site requests permission using the browser. As a rule, such a window appears on all sorts of online video chats, but this is if the site is white and clean.

If it is a fraudulent site or simply a hacked one to which exploits were uploaded, there will be no window. An attacker will be able to launch your webcam without your confirmation. In this case, try closing all browser tabs and repeating the search.

In more severe cases, this may also indicate that something was injected into the Google Chrome process. Yes, this often happens. In this case, you should reinstall the browser and continue searching for the Trojan on your computer.

I promise to tell you how to find malware on your computer in the next article, so if you don’t want to miss it, you can follow us on social networks.

That seems to be all. Now you know how to find out which application is using the webcam. By the way, this way you can determine the use of other devices on your computer.