CCTV (closed-circuit television) is a TV system in which the video signals are not publicly distributed but are monitored, primarily for surveillance and security purposes.
Effective CCTV surveillance relies on strategic placement of cameras, and observation of the camera's recordings. Previous generation CCTV systems were non-interactive and used small, low-resolution black and white monitors. However, latest & modern CCTV cameras are usually color, high-resolution with many technological advances, some of them listed below.
Computerized control, analytics and identification
Objects in the range of surveillance can be identified, tracked and categorized, thanks to such technological advancements.
Video Content Analysis – VCA
This is the capability of automatically analyzing video to detect and determine temporal events. VCA recognizes variations in the environment. VCA can even identify and compare objects in the database. The camera’s actions are usually programmed based on what it is "seeing". For example; an alarm can be trigged if an object has moved or missing from a certain area, , or if a smoke, fire is detected, or if running people are detected, or if someone has spray painted the lens, as well as video loss, lens cover, defocus, other illegal camera tampering events. VCA analytics can also be used to detect unusual patterns in an environment, example, to detect anomalies in a crowd, for instance a person moving in the opposite direction in airports where passengers are only supposed to walk in one direction out of a plane or in a train subway where people are not supposed to exit through the entrances.
VCA can track people on a predefined map. Once people are tracked on a map, it becomes possible to link many cameras and track any person through an entire building or map. This simplifies this person to be followed without having to analyze many hours of video footage. If the cameras are connected to a key-card system, person identities can be established and displayed as a tag over their heads on the video.
Facial recognition CCTV systems
Facial recognition in CCTV is a form of mass surveillance that is accomplished on digital CCTV systems by comparing selected facial features from the image over facial database(s) using enhanced face recognition computer applications. This type of system is useful to compare faces at airports and other entry ports with those of suspected criminals or other undesirable entrants
Wide range integration
Integrated systems allow different security systems such as CCTV, intruder alarms, access control devices etc. to operate centrally. For example, if an intruder alarm is activated, CCTV cameras covering the intrusion perimeter are recorded at a higher frame rate and transmitted to an Alarm Receiving Centre. Integration of such systems plays a very adaptive role in Crime prevention, Traffic monitoring & safety, retail operation, banking, schools etc.
Two-Way Control & Communication
Latest talk enabled CCTV systems allow overseers to speak to people within range of the camera's associated speakers. Mic enabled CCTV systems are used to get responses from the people in range as well as to record conversations onto the DVRs.
Advanced Storage and retention
CCTV systems usually record and store digital video and images to a digital video recorder (DVR) or, in the case of IP cameras, directly to a server, either on-site or remotely. The amount and quality of data stored on storage media is subject to compression ratios, video/image sizes. Storage is affected by the retention period of the videos/images. DVRs store images in a variety of patented file formats.