Closed Circuit Television (CCTV) is now common in commercial establishments, banks , home etc to monitor the premises for discouraging theft by recording the criminal activity. The system uses a video camera to transmit the signals to a specific place on a set of monitors. The signal is not transmitted open but transmitted to limited points through short range transmission. The receiver is connected to a TV. In wired system, RF cables are used to connect the camera directly to the TV. The Digital Video Recorders (DVRs) provide recording facility continuously with extra features like motion detection. The IP based CCTV has mega pixel sensors help to record the data directly to network attached storage devices for completely stand alone operation. High Definition CCTV (HD CCTV) system is now available to identify and track the objects in their field of view.
Wireless CCTV is popular now to avoid wiring in multiple places. Many cameras can be linked wirelessly to a single receiver system to monitor multiple places. These cameras do not require cable connection and only a power cable is necessary. The range of the transmission will be 100 meters or more in many types ideal to monitor multistoried buildings. The modern wireless camera uses digital technology to give crisper audio, sharper video and sends secure and interference free signals to the transmitter.
CCTV Camera is to be protected for its fail proof operation. Some costly types come with dust tight, pressurized, explosion proof casings. Presence of moisture, dust, grease etc can make the camera lens blurry to read. Laser light can easily destroy the camera so colour filters are used in some types.
The CCTV cameras do not require a video capture card and the signal can be directly saved into the computer through the USB port.MPEG format is usually used to make the video in compressed format. Computerized monitoring CCTV image is now developing so that the CCTV operator does not have to look into all screens continuously. These systems do not observe the people directly but track their behaviour body movements, clothing etc.
Closed-circuit digital photography (CCDP) is used for capturing and saving recorded high resolution images on a time lapse or motion detection basis. The images from such still cameras have more clarity than the video images. Images may be monitored remotely when the computer is connected to a network.
Facial recognition system verifies a person from the digital image for identification. This computerized system compares the selected facial features from the image with the facial data base.
(VCA) is another technique for the automatic analysis of video to detect and analyze temporal events not based on a single image. This system works like the visual cortex of human brain. The system recognizes changes in the environment and identifies and compares objects in the computer data base using the parameters like speed, colour, size etc. VCA analytics can also be used to detect unusual patterns in a videos environment. The system can be set to detect anomalies in a crowd of people like a person moving in the opposite direction in a protected area where people are only supposed to walk in one direction.