What is the full form of CCTV

CCTV: Closed Circuit Television

CCTV stands for Closed Circuit Television. It is also known as video surveillance. It is a system where all the elements, like video cameras, display monitors, and recording devices, are directly connected. It is used to monitor a sensitive area (A particular area which needs continuous observation and where there is no one to watch all the time). It is very helpful to prevent crime because it monitors all the activities and records them. It is also used for traffic monitoring by detecting congestion and noticing accidents.

CCTV uses wired or wireless transmission to send the signals or broadcasts to the monitor or recording device. It can transmit video, audio or both. Advanced CCTV cameras also have night vision capabilities to record low-light images. The CCTV signals are not publically distributed but are monitored for security purposes.

Basic Components of CCTV

• Security Cameras (Analog or Digital)
• Cables (RJ45 or RJ59 Cables)
• Video Recorders (DVR or NVR)
• Storage Unit (usually a Hard Disk)
• Display Unit (optional, usually a monitor)

Places where CCTVs are generally installed

• Banks
• Shops and multiplexes
• Casinos
• City Roads and Highways
• Building and Residential Apartments
• Corporate Houses
• Government Offices and Buildings
• Airports and Railway Stations
• Industrial plants etc.

The first CCTV was installed at Test Stand VII in Peenemunde in, Germany. It was installed by Siemens AG. The credit for the technological design and installation of this system goes to German engineer Walter Bruch.

Benefits of CCTV

• CCTV systems are a great deterrent to thieves. Once a thief realizes that he is under the surveillance of CCTV, he will prefer to go somewhere else.
• It reduces the fear of crime.
• It facilitates remote monitoring.
• It increases business efficiency and improves profitability.
• It can be used as the best option for home security.
• It also increases the risks for shoplifters.
• CCTV footage provides valuable assistance to the police in investigating crimes

How does CCTV Work?

Modern CCTV networks convert analogue signals to digital ones using hardware and software. Analog and digital systems operate very differently. Retrofitting is the practise of doing this.

Typical CCTV system components include:

• A single or more analogue or digital cameras, each with a lens and an image sensor
• A recorder, such as a typical video tape recorder for analogue systems or a network video recorder (NVR) or direct video recorder (DVR) for digital systems.
• Cables, either coaxial for analogue or RJ45 for digital
• A monitor or screen to which the images are sent

How does CCTV operate?

Using image sensors, a camera captures images through the lens.

Recorders may make use of analytical software and other intelligent technologies to scan the information and automatically alert users or other systems and devices. Video streams are captured, archived, and analysed using this video management software (VMS). The software frequently uses machine learning (ML) techniques that employ features like motion detection, facial recognition, people counting, etc., to learn on its own.

The monitor(s) may be observed passively (by software) or actively (by people). CCTV networks should and can be watched over.

Key CCTV Tech terms

Encoders for video: Analogue CCTV systems can be converted to some types of network systems with the aid of video encoders, giving customers access to more affordable hardware and cutting-edge features. Before delivering the video signals to a wired or wireless IP-based system, the application first authorises a wired connection and digitalizes the video signals.

Imaging technology: Cameras employ a variety of image sensors that convert light into electronic impulses. A sensor is made up of several photodiodes, commonly known as pixels. These photodiodes transform the light's exposure into an electron measurement. The two most common types are CCD (charged coupled device) and CMOS (complementary metal oxide semiconductor). Compared to CMOS sensors, CCD sensors are more expensive. In terms of quality, megapixel (using millions of pixels) CMOS sensors might even compete with CCD sensors.

CCD: These cost more and consume more electricity. CCD scanners are frequently the best option in low-light situations due to their superior light sensitivity and quieter operation than CMOS scanners. The signal is analogue, but an analogue-to-digital converter turns the pixel values into numeric values before the signal is broadcast.

Examining Pictures: While both CMOS and CCD sensors can be used for digital CCTV, CCD sensors typically employ an interlaced scanning technique (instant exposure). Analogue cameras only employ interlaced scanning. Interlaced: In this technique, the odd and even TVLs (where l stands for lines) from an image are transferred. This method is frequently used for CCD applications. Good resolution is provided by cameras with more than 400 lines, and high resolution is regarded by cameras with more than 700 lines. By periodically refreshing these messages, less bandwidth is used while yet deceiving the brain into thinking it is seeing a single, complete image. An interlaced image may appear jagged on a progressive scan monitor; this is correct when an interlaced recording is seen on an interlaced monitor. Modern video software first deinterlaces interlaced scans so that progressive scans can be produced that can be watched on both analogue and progressive scan monitors.

Progressive (common for CMOS applications): This method avoids segmenting the image into fields (odd and even lines). Instead, the image is scanned, and after that, a monitor shows each line in order (or field).

Recorders: DVRs typically connect to various internal components within the CCTV system rather than external networks. DVRs are frequently utilised with analogue cameras. In a DVR system, each camera must have a direct connection to the recorder.

NVR systems: Unlike DVR systems, which process video themselves, NVR systems encode and process data at the camera level before streaming it to the recorder for storage and remote monitoring. The majority of NVR systems use IP cameras. An NVR system's IP cameras are all linked to a common network.