Video Conferencing Cameras
Video conferencing cameras are special devices designed for use in video conferencing sessions.
There are two main categories of video cameras: consumer and professional. The first are designed for non-professional recording and include web cameras. The latter are used in video conferencing, on TV and in the film making process.
The resolution and quality: There are 4 main resolutions in hardware video conferencing systems: CIF (352×288), 4SIF (704×576), HD (HighDefinition – 1280×720) and FullHD (1920×1080).
Software video conferencing solutions often use QVGA (320×240) and VGA (640×480) resolutions. QVGA and CIF, VGA and 4CIF can be considered as relatively similar resolutions. The first got their origins from the resolution of the digital matrix, as in webcams, the latter are historically based on the standards of the television video signal (PAL and NTSC).
In recent years, video conferencing equipment that supports high-definition resolution and transmits a more realistic picture – HD (and then FullHD) began to appear on the market. Alas, HD quality demands much faster data transmission. Only devices with screen resolution not less than 1280×720 pixels can play HD video.
HD video conferencing cameras: There are several types of video conferencing cameras. They include professional PTZ cameras (with three degrees of freedom), web cameras, and IP cameras. All types of cameras can be both independent devices and integrated into the housing of certain equipment (cell phone, laptop, smartphone, videophone, video conferencing terminal, etc.).
PTZ cameras (Pan-Tilt-Zoom) are considered to be the most viable option for video conferencing in conference rooms and in cases where high image quality is required in any condition. These cameras do not compress the image and transmit it to the capture card or a video conferencing terminal without any delay. They also feature rotary device that allows you to aim the camera in the direction of the speaker during a video conference. The only disadvantage of PTZ cameras is their high cost, but it is justified if you take their versatility into account. Virtually all PTZ cameras can be controlled by remote control or with a special control panel with a joystick. PTZ cameras can save certain pre-programmed positions and focus on them in a fraction of a second, or automatically zoom on the speaking person by means of directional microphones.
Webcams are devices whose primary function is to capture an image in real time and transmit it over the Internet. Such camera may connected via the USB-port of a computer or already integrated into its case. Suitable for personal video conferencing. The main advantage of web cameras is their low cost, small size and the pre-digitized signal at the output. However, in contrast to the PTZ cameras, web camera digitizes and compresses the image, which is why there is a slight delay in recording and transmitting a video signal. Video coding artifacts may also be observed.
IP camera (InternetProtocol) is a network device that transmits video data in digital format through any computer network. IP camera has its own IP address in the network. In order to see the image fixed by such camera on your computer, it is often enough to enter an address of a certain user’s camera to a browser’s address bar. IP cameras are rarely used in video conferencing because of the signal delay, which occurs due to digitization and image compression. Delays are enhanced by camera’s network module, which is forced to substantially buffer the picture for a stable transmission over Ethernet-based networks, thus increasing the load on the network equipment, which is why video transmission over the network slows down.
Author: TrueConf Team