videcom CCTV Header have fun navigating the image H thing
AGC: See Automatic Gain Control

Alarm Input: An input signal that can enable an alarm trigger event, examples; start recording, generate audible alert, send email.

Analogue: A signal whose voltage level varies. For example Analogue Video in the UK (PAL CCIR Format) is a 1 volt peak to peak signal; the video component (the top 0.7 volt of the signal) varies according to the brightness of the image. 0.3 volt is black while 1 volt is white. The PAL standard has a limited resolution; horizontal resolution typically 330 TVL to 700 TVL is the number of voltage reference pints across the image.

Analytics: Software video image post processing enabling data collection or extrapolation for example Facial Recognition, Footfall, ANPR and a wide range of intrusion and motion detetion.

Angle of view: For CCTV cameras, refers to the angular range in degrees that you can focus the camera lens. The angle of view for a particular lens varies depending in the camera imager size. Lens manufacturers will quote angles of view for the standard imager size. The larger the angle of view the smaller individual objects will appear in the image, wide angle lenses, typically 4mm will give an overview while focal lenses over 12mm will provide a zoomed in image (based on 1/3 inch CCD)

ANPR: Software based Automatic Number Plate Reading or Recognition from a video image, live, still or recorded

Aperture: A function of the lens, an iris similar to the human eye is used to adjust the (opening) aperture of the lens, the wider the aperture the more light will pass though. When setting up a camera and lens, the distance the imager is set to is critical to maintain good focus. The lens needs to be set to the widest aperture before adjusting this setting. See Depth of field.

Auto Iris: A function of a CCTV camera lens in which the aperture automatically opens or closes to maintain proper light levels through the lens to the imager device. Two main types exist.

  • DD Direct Drive: The camera controls the lens motors directly.
  • AI Video Drive: The electronics to monitor the video are built into the lens.


Auto Electronic Shutter: AES; Circuitry within the camera to compensate for moderate light changes, normally only used in indoor applications without the use of auto iris lenses. Also see Electronic Iris.

Auto White Balance: AWB The camera will automatically correct colour based on a known point of reference. Some cameras require this reference setting at time of initial installation. Different settings are used depending on source light, for example sunlight, fluorescent tubes, sodium street lighting.

Automatic Brightness Control: ABC Automatically controls the level of brightness of a monitor or video image from a camera.

Automatic Gain Control: AGC An internal electronic circuit that automatically controls amplifier gain in order to produce a constant output. AGC can cause additional noise in an image in low light conditions. With AGC turned off a cameras image can be very dark when light levels drop.
Return to Top: Did you know Videcom also supply Boxed kit CCTV systems ?

Back Light Compensation: An image processing feature on most modern analogue and IP CCD cameras which electronically compensates for high background lighting to give detail. Allows processing of images with a light background, persons entering though a doorway lit from outside for example.

Bandwidth: The available capacity of a transmission path.
  • Analogue CCTV: The capacity of the link or cable to sustain the Video Transmission, the higher the camera TVL the greater the bandwidth requirement. Loss in bandwidth will affect camera resolution.
  • Digital CCTV: The available transmission space on an IP circuit. The amount of sustained IP data traffic the link can sustain. The greater the bandwidth, the more digital video that can be sent in a given amount of time, this can be higher frame rates or resolution.
Baud: Baud rate, refers to serial data transmission, RS232, RS485 & RS422 commonly used to transmit camera, keyboard and matrix control data in analogue based CCTV systems. Baud rate determines how many bits can be sent or received per second, typically 1200, 2400, 4800, 9600 and 19200. See Serial Communications for further information.

Binary: A base 2, number system which is represented by 0's and 1's. Commonly also referred to as bits. 8 bits make up a byte and 1024 bytes make up a Kilobyte. If we have an 8 bit binary number we can represent any value up to 255 of FF in hexadecimal, 1111 1111 in binary representing 128 + 64 + 32 + 16 + 8 + 4 +2 +1. Binary switches are often used to address CCTV devices.

Blooming: The defocusing or over brightness of regions of the picture caused by the an excessive level of light to part of the image, can be caused by headlights. In a camera, the sensor element saturates which causes widening of the spatial representation of a spot light source.

Videcom BNC BNC connector: Is a type of connector used to interconnect two coaxial cables or connect a cable with other CCTV components. Comes in variants specific for cable types and sizes and always best to use the mechanical crimp versions.

Brightness: The level of processed light in an image, this can be adjusted on a monitor or by post digital processing. Luminance is the correct electronic engineering term ,which has also been called brightness.)

Broadband:
  • Analogue: In television system use, a device having a band-pass greater than the band of a single VHF television channel.
  • IP: Provision of internet service typically over standard telephone lines ADSL.
Bullet Camera: A prebuilt camera assembly with a tube like shape, similar to a traditional camera with internal and external versions. Most bullet cameras come with infrared LED lighting. Available in analogue as well as IP HD versions. Burned-in-image: Also known as image burn. An image which persists in a fixed position in the output signal of a camera after the camera scene has changed or more common a persistent image on an analogue tube monitor screen. Not a common problem with modern CCTV systems due to CCD sensors and LED low energy monitors.

Byte: A unit of data consisting of 8 bits, used to store data, sometimes shown as a hexadecimal or binary number. With 8 bits it is possible to store a number from;
  • Hexadecimal 00 to FF
  • Binary 0000 0000 to 1111 1111
  • Decimal 0 to 255
Return to Top: Did you know Videcom also install Colour CCTV systems ?

Videcom CAT 5 Pinout Category (CAT) Cable: Four pair twisted data cable that is capable of transmitting IP and voice data at high speeds. CAT 5e and CAT 6 cable is commonly used for voice and data applications.

CCD: See Charge Coupled Device

CCTV: A closed loop surveillance system consisting of cameras, recording and monitoring equipment connected over a "closed" or dedicated cabling or transmission system. Used for visual monitoring, public safety, health and safety and security applications. Also used extensively in industry for plant monitoring and control, automated quality assessment and site security.

C Mount: A television camera lens mount of the 16 mm format, 1 inch in diameter with 32 threads per inch. Not commonly used anymore although many of the Town Centre lenses from major manufactures are still C mount and require an adapter ring for CS mount cameras.

CCTV: Common abbreviation for Closed-Circuit Television.

Charge Coupled Device: CCD image sensor, a scanning semiconductor matrix array that enables the transfer of light and colour into electronic format. Early CCD imagers suffered from image bleed across the sensor often seen as streaks or lines in the image in bright conditions.

CMOS: Complementary Metal Oxide Semiconductor. Similar to a CCD, it is also used to detect light for conversion into an electronic signal. Commonly used in modern IP HD CCTV cameras while CCD devices are more common in analogue cameras.

Coaxial Cable: A shielded cable with an outer shield core and centre signal carrying conductor. Commonly used to transmit analogue CCTV signals.

Codec: Short for compressor/decompressor, a codec is any technology for compressing and decompressing data. Codecs can be implemented in software, hardware, or a combination of both. Examples of Codecs algorithms include h264, Wavelet, Mpeg4 & Jpeg. Codecs are used to encoder analogue video signals into digital streams.

Videcom Video signal components Colour Burst: Part of the UK PAL video standard, this is a reference signal sent from the camera that allows the receiving equipment to lock onto a set frequency and enable the correct reproduction of the colour components within the image.

Colour Saturation: The degree to which a colour is free of white light.

Composite Video Signal: The combined picture signal, including brightness, colour, contrast together with vertical and horizontal blanking and synchronisation signals.

COMPRESSION: Contrast: The range of light to dark values in a picture or the ratio between the maximum and minimum brightness values.

CS-Mount: C & CS Mount cameras are designed to accommodate a separate custom lens to suit the surviellance application. The lens can be removed, exchanged or replaced. CS mount has become the normal mounting for modern CCTV cameras with C-Mount lenses requiring a small adapter ring to be fitted between the lens and a CS mount camera. CS lenses cannot be used on C-Mount cameras.
Return to Top: Did you know Videcom also install Digital IP CCTV systems ?

Day/Night Cameras: Day/Night Cameras` are cameras with an increased sensitive CCD chip that allow a good image to be captured in very low ambient lighting. Some Day/Night cameras will also include a mechanical infrared filter allowing them to become sensitive in ambient or additional infrared lighting. These cameras often have optically corrected filters or lenses to adjust for the focus shift that occurs with the different frequency of infrared lighting. Also see infrared.

Decibel: dB: The decibel (dB) is used to measure sound level, but it is also widely used in electronics, signals and communication. Gain (in dB) = 20 x Log (Voltage Out / Voltage In).

A +6dB Gain is equal to a 2x increase in the signal. A +12dB Gain is equal to 2 x 2 or 4 x increases in the signal. A +18dB is a 2 x 2 x 2 or 8x increase in the signal. When we express Gain as dB, every +6dB increase represents another doubling the signal. Many AGC circuits lomit the gain to 18 or 24dB to avoid to much noise in the resulting image.

Decoder: Depth of Field: The in-focus range of a lens or optical system. It is measured from the distance behind an object to the distance in front of the object when the viewing lens shows the object to be in focus. Depth of field can be affected by aperture size, with shorter depths of field or focus when a wider aperture is used. The technology of a pinhole camera demonstrates this well as an image will focus without a lens through a small pinhole.

Digital: There are two main ways of doing things electronically, analogue or digital. Digital is simply signals that are either on or off. A digital voltage or signal refers to the discrete nature of digital voltage potentials in digital circuits. Traditional logic circuits define 0.0 Volts as a logic 0 or low, and 5.0 Volts as a logic 1 or high. Modern circuits use lower voltages to enable higher data frequencies.

Digital systems: Nearly all CCTV systems installed are now fully digital, with network based cameras, computer hardware and IT infrastructure. Digital CCTV like modern television systems offer higher quality, greater recording capabilities and support for remote access. Videcom are a digital CCTV specialist combining traditional CCTV skills with modern networking, electronic and IT skills.

Digital Video Recorder: DVR, a digital video recorder is a hardware based device that converts the incoming camera video signal from analogue to digital, compresses it and store it. The DVR replaces the functions of a separate multiplexer and timelapse VCR. Also see NVR and VNR for network based CCTV recorders. DVR's are normally associated with analogue cameras with NVR's being the IP network recorders.

Digital Signal Processing: DSP, an image processing algorithm within the camera that digitizes data (the image). Examples include automatic compensate for backlight interference, colour balance variations and corrections related to aging of electrical components or lighting. Functions such as electronic pan and zoom, image annotation, compression of the video for network transmission, feature extraction and motion compensation can be easily and inexpensively added to the camera feature set.

Distortion: Often caused by signal loss or interference in cables, distortion can be measured but is also often visible by visual picture tearing, image jumping, or horizontal, vertical or diagonal lines. Image distortion is more prevalent in older analogue systems. Horizontal distortion or hum bars is often a sign of low frequency interference while vertical image distortion is normally attributable to higher frequency.

Distribution Amplifier: Only really required in analogue based systems or for SVGA monitor distribution. An amplifier will typically be used to distribute a camera or monitor signal to multiple users or pieces of equipment without loss or signal degradation.

Dome Camera: A camera with a dome like Perspex cover. Dome cameras come in many formats, win infrared or additional white lighting, often the camera of choice in large scale CCTV installations.

Duplex: DVR: See Digital Video Recorder.

Dynamic IP address: An IP address that is issued by another network managed device, this network address can be temporary and assigned to another device without notice. See IP address for further information. Typically a Wi-Fi laptop connecting to a router will normally be issued a dynamic address.

Dynamic Range: The difference between the maximum acceptable signal level and the minimum acceptable signal level. A camera with a wide WDR dynamic range is expected to provide a better signal to noise low light performance.
Return to Top: Did you know Videcom also install Energy saving Monitors?

Electronic Shutter: EI; Compensates through automatic exposure shutter speed changes for moderate light changes, best used in indoor CCTV applications without the additional cost if auto iris lenses.

Energy Saving: A critical part of any modern CCTV design, by using low energy monitors, green system disks, SSD devices a major saving in running costs can be made. Return to Top: Did you know Videcom also provde Fixed cost CCTV maintenance?

Facial Recognition: Post or live video analytical processing allowing the detection and matching of facial images from video, availabale as part of our VNR recording systems.

Field: One of the two vertically separated parts of the image into which a PAL video frame is divided. The image is made up of a number of odd and even lines in older CCTV recording systems only one field was recorded reducing the vertical resolution by 2. A PAL video system has 25 frames per second or a field every 20mS. Two fields make up an individual frame, in modern HD IP CCTV full frame transfer is possible this removes the requirement for fields, reducing motion blur and improves recorded resolution.

Field of view: The angle of view that can be seen through a lens or optical instrument.

Focal Length: Of a lens, the distance from the focal point to the principal point of the lens.

Footfall: People counting, Video Analytical software counting the number of people entering or exiting a shop or shopping area in a given time.

Frame: The total area, occupied by the television picture, which is scanned while the picture signal is not blanked.

Frames per second: FPS; the number of images that are recorded or displayed per second. The PAL system can display 25FPS and this is known as real time. Recording systems are adjusted to meet site operational requirements and available disk storage. By reducing frame rates disk usage can be reduced although with modern h264 compression this saving is not linear.

F-Stop F-Stop: The F-number (also known as focal ratio, F-ratio, F-number, or relative aperture) of an optical system is the ratio of the lens's focal length to the diameter of the light gathering opening (aperture). It is a dimensionless number that is a quantitative measure of lens speed, and an important part of CCTV lens design.


FTP: File Transfer Protocol, used to transfer files over a computer network. Used to transfer still images from IP cameras to a central server in the event of a triggered event, alarm, motion or time interval. Return to Top: Did you know Videcom also manufacture some Great RDC Cameras?

Gain: Gain is an electronic amplification of the video signal. This means that the signal is boosted electronically, adding more voltage to the pixels on your imager ("CCD or CMOS) causing them to get amplify their intensity and therefore brighten your image. This voltage increase is measured in decibels (dB) and is calculated using this equation:


Gamma: A numerical value, or the degree of contrast in a television picture, which is the exponent of that power law which is used to approximate the curve of output magnitude versus input magnitude over the region of interest.

Gigabyte: GB; This unit of data used to measure larger data storage or data transfer capacities by current standards.
Ghosting: A spurious image resulting from an echo, often caused by badly terminated coaxial cables where the image signal will "bounce" back on an unterminated cable end. Also seen in RF transmission systems, where a radio/TV signal is reflected back off buildings or nearby hills causing a ghosted second image to be received a few mS after the main signal

GPS: Global Positioning Satellite or System. Used to determine geolocation and time information. Used within our SceneVu Mobile RDC cameras to update user maps and camera locations. Return to Top: Did you know Videcom have many Happy Customers?

Hardware: The opposite of software; Electronic equipment, computers, camera housings, brackets, masts and other physical pieces of equipment.

HD: High Definition; Refers to CCTV cameras, recorders and monitors capable of displaying or producing High Definition images typically 1.3 MPixel and above.

Housing: A glass fronted enclosure for the camera, lens and sometimes additional control or telemetry hardware. More common used with older traditional analogue cameras where the cameras would be pre-built in our workshops.

Hum:Hum: Electrical interference or distortion normal at the power supply frequency or harmonics thereof. Often caused by earth potential difference between the camera and monitor where the coaxial cables provides a path for the differential in electrical supplies. The normal fix is to install an isolation transformer in line with the video cable isolation the two electrical systems. Normally apparent with vertical black or grey scrolling through the image, in severe cases will cause the picture to loose sync and roll. Return to Top: Did you know Videcom also manufacture some Great RDC Cameras?

Infrared: IR; Infrared illumination used for low light and night time CCTV. Active infrared lighting is used as it is outside of the visible spectrum. In some cases a small red glow can be seen from the infrared illuminators. Modern illuminators use LED illuminators that are lower energy and better matched to the frequency response of the cameras. In some cases an image under Infrared light can appear soft or out of focus, this is due to the different refraction of light through the lens at different light frequencies. This can be corrected my lens coatings or setting the focus of the camera under IR conditions.

Interference: Extraneous electronic noise which tends to interfere with the reception of the desired signals or combines with the source signal to distort or add noise to the image or audio source.

IP Video: Internet Protocol based video, digital CCTV systems from camera to recorder utilise IP Video, image resolutions are not limited by PAL standards.

IPS: Images Per Second; The rate of individual images from a camera per second. Real time is typically 25ips or 25 Frames per second (50 fields). Many IP HD cameras are limited to 12 ips to reduce bandwidth and recording disk usage.

Iris: An adjustable aperture built into a camera lens to permit control of the amount of light passing through the lens. Also see Auto Iris.

IVA: Intelligent Video Analytics, producing data from the video stream for analytical purpose.
Return to Top: Did you know Videcom use FTP to upload JPEG images to use as webcams and review of SceneVu cameras?

JPEG: Image compression standard `Joint Photographic Experts Group` who designed the standard. This is a standard way of compressing images which works particularly well for photographic and still images.

Jitter: Small and rapid variations in a waveform due to mechanical disturbances or to changes in the characteristic of components. Supply voltages, imperfect synchronizing signals, circuits. Cn be seen in a CCTV image as a vibrating image.

Joystick: A 2 or 3 axis moveable control stick used to control PTZ cameras. Return to Top: Did you know Videcom also manufacture some Great RDC Cameras?

Kilobyte: This unit of data used to measure larger data storage or data transfer capacities by current standards. 1KB = 1024bytes. Also see byte, Gigabyte, Megabyte & Terabyte. Return to Top: Did you know Videcom also support many Legacy CCTV systems?

LAN: Local Area Network, normally hardwired joining computers together to allow the sharing of resources and data.

LCD: Liquid Crystal Display. Liquid crystal displays (LCDs) now the mainstream of CCTV display with the demise of the traditional CRT, LCD monitors offer smaller footprint, lower energy and higher display resolutions. LCD monitors are capable of displaying full HD CCTV cameras.

LED: Light Emitting Diode, electronic component capable of producing a specific light output visiable and infrared. Modern LED lights are very energy efficient and used in both office lighting and infrared CCTV illuminators. LED technology is also used in latest generation low energy monitors.

LENS: A transparent optical component consisting of one or more pieces of optical glass with surfaces so curved (usually Spherical), that they serve to converge or diverge the transmitted rays of an object, thus forming a real or virtual image of that object.

LENS SPEED: LIGHT: Electromagnetic radiation detectable by the eye, Visible light ranging in wavelength from about 400 to 750 nm. With Infrared between 750nM and 1000nM

LOOP THROUGH: The feeding through of an analogue video signal to more than one device for example a single camera signal will be looped though a DVR onto a Matrix. Only the last device in the chain should be terminated.

LOSS: A reduction in signal level or strength, usually expressed in dB. Losses can be caused by cable length as well as bad or poorly made joints and connections. Analogue systems tend to suffer more from loss thoughout the system.

LPR: Licence Plate Recognition or Reading, also see ANPR;

LUX: International System (Si) unit of illumination in which the meter is the unit of length. One lux equals one lumen per square meter. Camera low light performance is shown in lux, for example Colour 0.3 Lux & mono 0.1 Lux, this needs to be compared at the same lens F stop for accurate comparison. A sunny day is around 100,000 lux, a full moon lit night around 0.1 lux with street lighting approximately 1 to 10 lux. Return to Top: Did you know Videcom supply Monitor walls for control rooms?

MONITOR: A unit of equipment that displays on the face of a picture tube the images detected and transmitted by a television camera.

MBPS: Megabits Per Second; Measurement of the transmission speed of data measured in 1,048,576 bits per second.

Megabyte: This unit of data used to measure larger data storage or data transfer capacities by current standards. 1MB = 1024KB = 1,048,576 bytes. Also see byte, Kilobyte, Gigabyte & Terabyte

MJPEG: Motion Joint Photographic Experts Group; also see JPEG. This compression standard generally refers to JPEG images shown as a sequence of images to make up a moving video. Many older DVR units recorded using the JPEG algorithm, but modern H264 video compression has become the modern standard.

Modem: A device not commonly used anymore, used to connect a data network over standard telephone lines, typically RS232 data. Can still be seen on remote sites for data collection.

Modulation: The use of a carrier frequency to transport information. The higher frequency carrier frequency has the amplitude (level) adjusted, this level represents the data. RF FM modulation is used for example to carry voice and music over radio signals.

Monitor: A monitor is used to display camera images, data from computer systems and other visual information.

Monochrome: Black and white with all shades of grey. In video terms a signal without colour, monochrome CCTV cameras are often also sensitive to infrared. Analogue monochrome cameras are typically more sensitive to light and higher resolution than colour.

MPEG: Motion Picture Experts Group; MPEG is an international standard for video compression. MPixel: Megapixel; A million Pixels, see Pixel. HD cameras are typically 1.3 MP or above with 1.3 million individual points within the image.

Multiplexer (CCTV): Designed to record and/or display multiple cameras. VCR multiplexers, now superseded by DVRs, were common place in systems consisting of multiple cameras. The video images were interleaved rapidly, in sequence and recorded to tape. The limitation of these systems was the available frame rates of the receiving video recorder, typically 25 IPS, meaning with 16 cameras the record rate was less than 2 IPS per camera. Return to Top: Did you know Videcom also manufacture some Great RDC Cameras?

NNNNN Return to Top: Did you know Videcom install a range of Great ONVIF cameras?

ONVIF Open Network Video Interface Forum; Originally started by Axis, Bosch & Sony to deliver standards within the IP CCTV industry. Return to Top: Did you know Videcom also manufacture some Great RDC Cameras?

PPPPP Return to Top: Did you know Videcom also manufacture some Great RDC Cameras?

QQQQ Return to Top: Did you know Videcom also manufacture some Great RDC Cameras?

RDC: Rapid Deployment CCTV and Cameras. Typically connected over mobile data 3G or 4G, Broadband or Wi-Fi. Typically a standalone CCTV solution that can be rapidly deployed for short duration surveillance. Please see our SceneVu Mobile cameras for forther information. Return to Top: Did you know Videcom also manufacture some Great RDC Cameras?

Saturation: Colour, the ammount to which a colour is diluted with white light or is pure. The vividness of a colour, described by such terms as bright, deep, pastel, pale, etc. Saturation is directly related to the amplitude of the chrominance signal.

Serial port: A computer I/O (input/output) port through which the computer communicates with the external world. The standard serial port is RS-232 based and allows bidirectional communication on a relatively simple wire connection as data flow serially.

Shutter: Ability to control the integration (of light) time to the sensor to less than 1/50 second; e.g.: stop motion of moving traffic. High shutter speeds are used to stop motion blur when viewing fast moving objects. Higher shutter speeds required more light.

Signal to Noise ratio: (S/N), The ratio between useful television signal and disturbing noise or interference signals.

Smart Cities: The use of modern technology including CCTV and Video Analytics to manage city infrastructure including traffic flow, civil unrest, pedestrian movement and emergency planning, smart City.

Snow: Heavy random noise, normally appears within image as white dots ir patches.

Spike: A transient of short duration, comprising part of a pulse, during which the amplitude considerably exceeds the average amplitude of the pulse. Seen as a spike withing the normal signal.

Standard Minimum Signal: 1000 microvolts at 75 ohms (0dB mV) in RF systems; 0.7-VPP non-composite, 1-VPP composite in video systems. Return to Top: Did you know Videcom also manufacture some Great RDC Cameras?

Tearing: A lateral distortion in the video image due to sync instability. It appears as though parts of the images have been torn away, generally caused by interference or earth potential problems between the camera and monitor.

Telemetry: In CCTV systems describes the control data that is used to manipulate the cameras functions, for example Pan, Tilt, Zoom, Focus. Some cameras support multiple manufacturer protocols with Pelco D and Pelco P being commonly deployed on many cameras, telemetry can be transmitted over RS485, RS422 and RS232 as well as signals sent over the coaxial cables and older systems that use DTMF tones as used for telephone tone dialling. Alarm data is also transmitted back on some systems through the telemetry data network.

Termination: This usually refers to the physical act of terminating a cable with the correct impedance for example PAL CCTV 75 ohm, RS 485 data 120 ohm. Or the use of the correct terminating connectors BNC for example. PAL video must be terminated at the end of the signal path otherwise reflections or over brightness can occur.

Time lapse: The recording or display of video with frames removed, typically used for long duration recording to extend the life of the recording. CCTV is often viewed live yet recorded for 31 days at a reduced, time lapse, frame rate for example 6 images per second (ips).

Transformer: A device to change AC Voltage, will typically reduce 240 VAC to 48, 24 0r 12 VAC.

Twisted pair: Describes a pair of cables typically used to carry data or voice, where the cable cores are twisted together while remaining insulated. When interference is picked up on the cable it will be the same on both cores and can be easily removed by the use of comparison electronics. Typically twisted pair data signals will have opposing polarity with core A going positive and Core B negative. Any spike or interference will appear with the same polarity on both cores and can be easily identified and rejected. Return to Top: Did you know Videcom also manufacture some Great RDC Cameras?

Unbalanced signal: In CCTV, this refers to a type of video signal transmission through a coaxial cable. It is called unbalanced because the signal travels through the centre core only, while the cable shield is used for reference and shielding.

Underscan: Decreases screen size H and V so that all four edges of the picture are visible on the monitor, this ensures that all of the PAL image is displayed.

UPS: Uninterruptible power supply. Power supplies used in the majority of high security systems, the purpose is to back-up the system power during power outage. The duration of this depends on the size of the UPS, usually expressed in VA, and the power consumption of the system. Sometimes a local low voltage power supply with internal battery will be fitted.

URL: URL is the abbreviation of Uniform Resource Locator. It is the global address of documents and other resources on the World Wide Web.

UTP: Unshielded twisted pair. A cable medium with one or more pairs of twisted insulated copper conductors bound in a single sheath. Return to Top: Did you know Videcom install a wide range of Video Surveillance Cameras?

VCA: Video Content Analysis, for example used for video motion detection, object left and object removed alarms. Speed analasis and people counting.

VCR: Video Cassette Recorder, now long in the tooth and mostly removed from service, the workhorse of traditional CCTV systems, a method of recording video to magnetic tape.

VMD: Video Motion Detection.

VNR: Videcom Network Recorder. Part of a family of CCTV IP and analogue video & audio digital recorders. The VNR software is deployed throughout a range of CCTV products including our SceneVu range and VNR ANPR, VNR Analytics, Wall drivers and virtual matrix solutions.

VRM: Vehicle Registration Mark (Number Plate).

VRN: Vehicle Registration Number (Number Plate).

Video Surveillance: Similar to CCTV, a term used to describe the use of Closed Circuit Television cameras to provide external surveillance of a target.

Video Test Pattern: Special test pattern for adjusting colour TV receivers or colour IP encoders. The test pattern contains standard colours as well as resolution lines and shapes to help confirm the setup of a monitor.

Return to Top: Did you know Videcom also install some Great WI-Fi transmission equipment?

For Wireless IP terms please refer to our separate section here on our main site

Wavelet: Video compression format that was poipular before h264 and is a popular compression for CCTV. It offers higher compression ratio with equal or better quality than MJpeg, h264 is now the mainstream recoding compression.

White Balance : Electronic circuit and processing designed to produce correct colour reproduction, CCTV cameras will automatically attempt to correct colour in different lighting conditions.

Wireless : A method of transmitting digital data, voice or video without wires. Typically refers for modern Wi-Fi based CCTV.

Return to Top: Did you know Videcom also manufacture some Great RDC Cameras?

XXXXXX Return to Top: Did you know Videcom also manufacture some Great RDC Cameras?

Y/C: A video format found in old Super-VHS tape video recorders. Luminance is marked with Y and is produced separate to the C, which stands for chrominance. Thus, an S-VHS output Y/C requires two coaxial cables for a improved output. Return to Top: Did you know Videcom also manufacture some Great RDC Cameras?

ZZZZZ