IP Video Surveillance

An Internet protocol camera, or IP camera, is a type of digital video camera employed for surveillance, and which unlike analog closed circuit television (CCTV) cameras can send and receive data via a computer network and the Internet. Although most cameras that do this are webcams, the term "IP camera" is usually applied only to those used for surveillance.

There are two kinds of IP cameras :

1. Centralized IP cameras, which require a central Network Video Recorder (NVR) to handle the recording, video and alarm management.
   
2. Decentralized IP cameras, do not require a central Network Video Recorder (NVR), as the cameras have recording functionality built-in and can thus record directly to digital storage media, such as flash drives, hard disk drives or network attached storage.

Several types of network cameras are used in ip video surveillance systems, depending on the specifics of their implementation. The most traditional type cameras are wall mountable with fixed angle of the image. When installing outdoors, surveillance IP cameras may be installed in housing and thus be protected from adverse weather effects. Static constraints of this type of network cameras can be overcome with the use of PTZ (Pan, Tilt and Zoom) cameras for moving objects or vehicles. As evidenced by their name, the camera can operate in standby view, tilt and zoom manually or automatically. Movements are guided by an operator monitoring video images of control room. Dome PTZ cameras are another type used in video surveillance systems. Extensive territory is in their cover, thanks to greater flexibility in work arrangements in view, tilt and zoom. Unlike other PTZ cameras, PTZ dome camera allows 360 degrees pan and tilt 180 degrees while moving automatically between predefined positions. This kind of cameras are mounted on a ceiling - where conditions indoors, or on a pillar or corner - when used outdoors.

Variety of such models are PTZ cameras with electronic realization of the movement in which the operator can choose view mode, zoom in or slope without the need for the camera itself to move. Immediate movement and change of image is an advantage, compared to mechanical PTZ cameras in which the transfer takes a period of about one seconds.