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Glossary

ActiveX

A Microsoft open technology for windows-based applications. ActiveX controls can be downloaded as part of a Web document to add functionality to the ActiveX-enabled browser.
AES

Automatic Electronic Shutter, the sensor will automatically adjust the sensitivity according to the changes in illumination of detected area.
AF

An ability by which the camera lens automatically adjusts its focus on the captured subject.
AGC

Automatic Gain Control, an electronic circuit which amplifies the video signal when the signal strength falls below a given value due to the lack the light on the image device.

Angle

The area of view, measured in degrees. It is the view that a lens can cover in practical usage. A short focal length has a wide-angle.
Aspect ratio

The ratio of width to height of a screen or video picture. Most TVs and monitors have a 4x3 aspect ration-- the screens are 4 units wide and 3 units high.

Auto IRIS

A special type of IRIS, is used to adjust the amount of enter light, electrically controlled by the camera.There are two main types of AutoIRIS - Video and DC IRIS. See also Video IRIS and DC IRIS.

AVI

Audio Video Interleave, a Microsoft multimedia file format. An AVI file contains both audio and video data in a standard container that allows simultaneous playback.

AWB

Automatic White Balance, is used in digital camera to automatically compensate the type of light (daylight, fluorescent, incandescent, etc.,) or lighting conditions in the scene.To make it normal for the human eye.

Bitmap

A storage way of digital image. A bitmap is created whenever an image is scanned and defines a display space and the color for each pixel or bit.It can then be saved as a JPEG, GIF or other type of file.
Bit rate

A unit of speed, defines the number of bits/ time unit, usually expressed in Kbit/s or Mbit/s.
Broadband

It is used to mean high-speed data transmission in popular terminology. For network terms, this defines transmission methods where two or more signals share the same carrier.
CCD

Charged Coupled Device, an electronic detector made of silicon that converts light energy into electronic signals. It is used in many digital cameras for image detection.

CE

Consultants Europe, is a Technical and Legal organization specialized in the CE marking, CE certification and Authorized Representation of products.

CGI

Common Gateway Interface, A set of rules that describe how a web server communicates with other (CGI) programs.

CIF

Common Intermediate Format, a video format used in analog video. The resolutions are 352x288 pixels for PAL and 352x240 pixels for NTSC.

Client/server

A program or Internet service in which individual computers (clients) use a central computer (server) for services. For example, a web browser is a client program that requests the service of sending a web page or files from a web server.

CMOS

Complementary Metal-Oxide Semiconductor, one type of image sensor found in digital cameras.CMOS chips are easier and cheaper to make than CCDs but don't match the picture quality generally.

Coaxial cable

It is an electrical cable that consists two conductors, separated by an insulating layer. It is used to transmitting analog video in a CCTV system.

Codec

Codec stands for Coder/ Decoder, which converts analog video and audio signals into a digital format for transmission.The codec also converts received digital signals back into analog format.

Composite Video

Composite video is a signal that contains the luminance (brightness), chrominance (color), blanking & sync pulses and color burst information of displayed image.NTSC and PAL are examples of composite video standards.

Contrast

Contrast is usually defined as a ration between the darkest and the brightest spots of an image in image processing.Images have a higher contrast level generally display a greater degree of color grayscale variation than those of lower contrast.

CPU

Central Processing Unit, the central unit in a computer containing the logic circuitry that performs the instructions of a computer's programs.The speed at which the CPU processes information internally is measured in MegaHertz (MHz) and GigaHertz (GHz).

CS-mount

An industry standard for mounting a lens on a camera. The distance from the flange surface to the focal points is 12.5mm.

Day and Night IR LENS

The camera with this feature will automatically detects available light and instantly adjust the brightness and gain under low light condition by switching to Infra-Red(IR) black and white mode.
dB

Decibel widely used to measure the loudness of sound. The decibel is more generally a measure of the ratio between two quantities,and can be used to express a variety of measurements in acoustics and electronics.
DC

Direct Current is the type of electricity. All of the electric charges move in one direction.
DC IRIS

One type of Auto IRIS, will automatically adjust the amount of light allowed to enter. It requires simply a DC input from the camera without signal converted.
DDNS

Dynamic Domain Name Service is a service that maps Internet domain names to IP addresses. It works with dynamic IP addresses.
Decoder

A decoder is a device that is undoing the encoding so that the original information can be retrieved. Just as the reverse of an encoder.
De-interlacing

A process that converts interlaced signals into progressive signals. The interlaced video must first be de-interlaced to produce progressive video for viewing in a progressive video system.
DHCP

Domain Host Configuration Protocol: is a protocol for automatically assigning dynamic IP addresses to individual devices on a network. A device can automatically be given an IP address each time it connects to a network with DHCP server.DHCP server also assigns the subnet mask, Default Gateway, and Domain Name Server IP address.
DI

A Digital Input will detect a voltage or no voltage condition, and generates a logical 0 or 1, high or low. It could be used to trigger an alarm or other events.
DO

To trigger an output alarm, the digital output will short both pins and complete the external device's circuit. The normal state is open.
Digital Zoom

Digital Zoom takes part of the image and expends it. The resulting image appears bigger but not as sharp as with an optical zoom.
DNS

Domain Name System translates Internet domain and host name into corresponding IP addresses. It only works with static IP addresses.
Domain server

To centralize the management of the Windows computers by using Domains. The domain server is the server that takes control of the users' accessing on the network.
D-SUB

D-sub is used to indicate the type of connector for the VGA interface.
Electronic shutter

One of the major features of CCD cameras, works with the IRIS setting. It eliminates the blurry image of fast-moving subjects in higher shutter speeds.

Encoder

An encoder is used to encode a bitstream into a form that is acceptable for transmission. Inside video cameras, that changes individual component signals into composite signals.

Ethernet

Ethernet is the most widely used in local area network technology. It is also used in wireless LANs. There are 10BASE-T and 100BASE-T system for Ethernet, the transmission speeds up to 10Mbps and 100Mbps respectively.

f

Used to indicate the range of focal length, such as f 2.4~24mm. See focal length.

F

Used to indicate the size of IRIS. See IRIS.

Factory default settings

The original setting for a device when it was first delivered from the factory. Sometimes, it is necessary to completely reset the settings changed by the user to factory default settings.

FCC

Federal Communications Commission; is responsible for administering the television and radio airwaves, satellite and cable transmissions, and telegraph communications.

Firewall

A program or hardware that prevents unauthorized access to a network or an individual computer.

Fixed iris

Fixed IRIS lens is one kind of iris and with fixed size IRIS.

Flash ROM

A type of read-only memory, which can be erased and reprogrammed or by loading new software.

Focal length

The distance between a lens and its focal point. Usually expressed in millimeters, smaller focal lengths result in wider fields-of-view.

Format

For image process, referring to the type of computer format in which the electronic image has been saved, i.e., JPEG, TIFF, etc.

Frame

It is a complete video image. A video frame is made up of two interlaced fields of either 525 lines (NTSC) or 625 lines (PAL).

Frame Rate

The rate at which video frames are displayed on a monitor per second. Frame rate for PAL is 25 fps, and frame rate for NTSC is 30 fps.

FTP

File Transfer Protocol: A TCP/IP protocol specifying the transfer of text or binary files across the network.

Full-duplex

A system that allows both directions transmission at once. It requires dual communication paths between two devices.

Gateway

A gateway is a network point that acts as an entrance to another network. It is often associated with a router to furnish the path for packets in and out of the gateway.

GIF

Graphics Interchange Format, a standard format for compression of images. GIF is commonly used on the web because it employs an efficient compression method.

H.261

An early video codec standard that is in heavy use in videoconferencing applications.

H.263

An update of the H.261 video codec standard, H.263 is also used primarily in videoconferencing and goes with higher quality than H.261.

Half-duplex

Data can be transmitted in both directions, but not at the same time.

HTML

Hypertext Markup Language is a language to specify the structure of documents for displaying in web browser.

HTTP

Hypertext Transfer Protocol is a request/response protocol between clients and servers.

HTTPS

HTTP over SSL, a kind of web protocol. It is used to encrypt and decrypts the user page requests and the pages that are returned by the Web server.

Hub

It is used in a wired network to connect Ethernet cables from multiple devices. Each device can talk to the others.

Hue

It is an attribute of color and the other two elements are brightness and saturation.Hue differences depend primarily on the variations of wavelength and defined by its dominant wavelength.

Image compression

Image compression is used to reduce the file size (in bytes) of an image. There are several methods of image compression, such as JPEG and MPEG.

Interlacing

A process that divides each video frame into two fields. The odd numbered lines to be field one and all the even numbered lines to be field two. Interlaced video uses two video fields to make a single frame of video.

Infrared

Infrared radiation is a radiation of a wavelength longer than visible light, but shorter than microwave radiation. The color cameras can detect the infrared radiation by the heat and capture it.It will filter the infrared radiation by IR-cut filter and prevent the distortion.Under low illuminance or night, the cameras will remove the filter and allow infrared radiation to hit the image sensor and produce images.

IP

Internet Protocol; is the main network layer protocol used on the Internet. It defines how information gets passed between systems across the Internet.

IP address

Internet Protocol address; is a unique number that devices use to identify and communicate with each other on a network, which uses the Internet Protocol standard.

IP Waterproof Rating

IP66IP68, The IP rating means that product is protected against the ingress of solid object and water. Many cameras or camera housings are designed for outdoor use, and therefore need to be waterproof. The first digital is the protection against solids, and the second digital is the protection against water. Refer to the above table for details;

IR Cut filter

Infrared-radiation cut filer, is a color filter used in color CCD or CMOS, in order to block the infrared light and make the colors more realistic.

IR LENS

A kind of lens; used in the color cameras for detecting the Infrared radiation. See also Infrared (IR).

IRIS

The circular aperture that controls the amount of light passing through to the camera's sensing element.

ISMA

ISMA is a global alliance driving the integration of multimedia IPTV standards. It's goal is: "To accelerate the adoption and deployment of open standards for streaming rich media content such as video, audio, and associated data, over Internet protocols."

JPEG

Joint Photographic Experts Group is an image compression format for images. Unlike other formats, it is a lossy compression technique.

kbps

Kilobits per second, a unit of network connection speed. (1 kbps equals to 1,000 bits per second).

kBps

Kilobytes per second, a unit of network connection speed. (1 kBps equals to 1,000 bytes per second).

LAN

Local Area Network; is a network that allows multiple computers or other devices to be connected to each other. In order to share data or a resource or file storage space.

LED

Light Emitting Diode, a semiconductor used to convert information from electrical to optical form, typically as an indicator light.

LENS

A lens is a device, usually made up by a piece of shaped glass. It is used to concentrating or diverging light.

Linux

An open source operating system based on UNIX. It is popular in web server and other high-performance computing environments, and has recently begun to gain popularity in workstation environments as well.

Lux

A measure of visible light intensity taken at the surface that the light source is illuminating. (1 lux = 1 lumen/square meter).

MAC address

Media Access Control address; is one unique code assigned to a networking device. For example, the network card in a computer has its own MAC address.

Manual iris

One kind of iris, opposite of an AutoIRIS. Manually adjust the camera iris to regulate the amount of light allowed to reach the image sensor.

Mbps

Megabits per second, a unit for network connection speed. (1 Mbps equals to about one million (1,048, 576) bits per second).

MBps

Megabytes per second, a unit for network connection speed. (1 MBps equals to about one million (1,048, 576) bytes per second).

Megapixel

Pixel element is used to display the images captured from digital cameras. The Megapixel is generally equal to one million pixels.

MJPEG

Motion JPEG is a video codec consisting of a sequence of individual JPEG images. The image quality is independent from the motion of the image that differs from MPEG video.

Modem

A device that allows two devices to communicate over telephone lines.

Motion Detection

Motion detection is used to trigger motion events. Enable it by adding a new detected window, window name, sensitivity and percentage.

MPEG

Motion Picture Experts Group standard that specifies a variable rate compression algorithm that is used to compress full-motion image sequences at low data rates.

MPEG-2

MPEG-2 is one compression standard and is used to encode audio and video for broadcast signals.

MPEG-4

MPEG-4 is the latest graphics and video compression algorithm standard developed by MPEG. These standards made interactive video on CD-ROM, DVD and Digital Television possible.

MPEG-4 Short Header Mode

One compression method of MPEG4, encapsulates the H.263 video stream in MPEG-4 video stream headers. For practical purposes, MPEG4 short header is identical to H.263.

MPEG-4 Simple Profile

One kind of MPEG4 Profile, used to specify which method the MPEG4 decoder would support. It supports I-, PVOPs (frames),CIF resolution and 384 kbit/s. (at the L3 level).

Network connectivity

The connection between the physical and logical for a computer network or a network device, i.e. the Internet or a LAN.

NTP

Network Time Protocol, an Internet standard protocol used for synchronizing network device clock.

NTSC

National Television Systems Committee is the most popular video display standard in North America.NTSC uses 525 TV lines per frame and frame rate is 30 frames per second.

NTSC 4.43

Similar to NTSC. The output power for NTSC 4.43 is 4.43 MHz. (NTSC is 3.58 MHz).

Optical Zoom

Optical zoom amplify the image size by adjusting the lens. It enlarges the subject without sacrificing resolution.

PAL

Phase Alternating Line, is a video display standard used in Europe and certain other parts of the world.PAL uses 625 TV lines per frame and frame rate is 25 frames per second.

PAL 60

Similar to PAL. The output power for PAL 60 is 60 MHz. (PAL is 50 MHz).

PAN

The pan function will reposition the focus on different areas of a camera image.

Patrol

The camera patrols between the preset positions on the Patrol List, which can be modified on the "Camera control page". After one patrol cycle, the camera returns to the original position.

Ping

Packet Internet Groper, a command used to test the availability of a host on a network or on the Internet. It works by sending a packet to the specified address and waiting for a reply.

Pixel

Stands for picture element, the smallest bit of data in a video image.

PoE

Power over Ethernet, a technology used to transmit electrical power along with the data.It is used in IP-Surveillance and remote monitoring in places where it is inconvenient to feed the devices power from a power outlet.

PPP

Point-to-Point Protocol, a protocol used to communicate between two network devices by using a serial interface.

PPPoE

Point-to-Point Protocol over Ethernet, is a protocol for network devices to communicate by establishing a DSL link connection with the ISP.

Pre/post alarm images

The image before and after an alarm is triggered. Those are stored in a buffer for later use, such as sending snapshot or recording.

Progressive scan

The opposite of interlaced scan, a method that electronically draws the video picture in one complete pass, rather than the two odd and even passes of interlaced video.

Protocol

A standard that specifies the format of data and rules for two devices to connect and transmit data to one another. Low-level protocols define the electrical and physical standard. High-level protocols proceed data format, such as TCP and IP.

Proxy server

A server that provides the service for clients to make indirect network connections to other network services. Proxy server will save the previous data or resource in a cache when the request is made for first.To provide it when the same request is made again. It could be used to avoid occupying much bandwidth.

QCIF

Quarter CIF, or Quarter Common Intermediate Format. It refers to video with dimensions of 176 by 144 pixels usually.

QSIF

Quarter SIF, or Quarter Source Intermediate Format. It refers to video with dimensions of 176 by 120 pixels usually.

Quad view

A quad view displays the images from four cameras on a single screen at the same time, where each image displays a quarter of the display area.

RAM

Random Access Memory, a temporary storage area for the processor uses to execute programs and keep data.Once the RAM is full, it will remove the information to make space for performing the current mask.

Resolution

The number of pixels displayed on the screen. This is defined by two numbers that indicates the number of pixels displayed horizontally multiplied by the number of pixels displayed vertically.

Router

A router is a device, determines the next network point for a packet should be carried to its destination.

ROM

Read-Only Memory is one kind of memory. The inside data could only be read but not written.

RS485

RS-485 is an electrical specification of a two-wire, half-duplex, multipoint serial connection.It supports high data transmission speeds and uses a different balanced line over twisted pair. It also spans large distances.

RTCP

Real-Time Control Protocol is used to monitor the session. It is mainly used to feed the streaming server with reception statistics from the client.The server may then decide to use these statistics (such as the numbers of lost packets, the delay from reception) to adapt its strategy.

RTP

Real-time Transport Protocol is the protocol used to transport the multimedia stream to the client. It sends a packet to the network but cannot warrant that the packet will reach its destination.

RTSP

Real-Time Streaming Protocol is mandated to manage the streaming session. This is called the Internet Remote Control. It allows the client to know about available streams at a location, get stream parameters...etc. It also allows to PLAY, PAUSE, STOP, just what you generally expect from a remote control.

Saturation

A measurement of chrominance, or the intensity of color in the video signal.

SDRAM

Synchronous Dynamic Random Access Memory, all input and output information is synchronized to a master clock signal.

Server

A server is a computer program that provides services to other computer programs and their users. Such as web server and mail server.

Sharpness

Sharpness describes the clarity of detail in a image.

SIF

Standard Image Format, usually used to refer to video frames with dimensions of 352x 240 pixels for NTSC and 352x288 for PAL.

SMTP

Simple Mail Transfer Protocol: The main protocol used to send electronic mail from server to server on the Internet.

Subnet & subnet mask

A subnet is used to identify separate part of an organization's network. On TCP/IP networks, subnets are defined as all devices whose IP addresses have the same prefix. It is used for security and performance reasons.

Switch

A switch is a network device that selects a path for sending a unit of data to its next destination.

S/N ratio

The ratio of the value of the signal to that of the noise (expressed in decibels). The higher the number, the better.

TCP

TCP enables two hosts to establish a connection and exchange streams of data and guarantees that packets will be delivered in the same order in which they were sent.

Telnet

A TCP/IP protocol for creating a connection to a remote server. The commands will be executed if they are entered from the remote computer's console.

Tilt

Rotating the camera upward or downward.

TVL (TV Lines)

TV Lines is used to define the resolutions in analog video. The higher TVL value, the sharper the image.

UDP

User Datagram Protocol is a communication protocol used for data transmission between network devices.UDP does not provide mechanisms for error detection and error correction between the source and the destination.

UPnP

Universal Plug and Play is a set of computer network protocols. It allows devices to be attached or removed from the system, even with the power on.

URL

Uniform Resource Locator is used to specify addresses on the World Wide Web. The first part of the address is protocol and the second part specifies the IP address or the domain name where the resource is located.

USB

Universal Serial Bus is a plug-and-play interface between a computer and peripheral devices. It supports 12 megabits per second for data transmission.

Vandal-proof

To completely avoid the camera from external impact and make it ideal for video surveillance outdoors.

Varifocal lens

A lens, that has a variable focal length that can set manually.

Video IRIS

One type of AutoIRIS, a video iris lens has an amplified circuit for converting input video signal to a DC input for the camera.

VPN

Virtual Private Network is a private communications network often used within a company.

VOP

Video Object Plane, a VOP is an image frame of an MPEG-4 video stream.

WAN

Wide Area Network, a collection of local area networks connected by a variety of physical ways. The Internet is one example of WAN.

Weather-proof

A protection for the camera from the adverse environmental conditions.

Web server

A web server is a program installed on a computer that is connected to the Internet. It is used to provide the service for web browser's request from computers connected to the Internet. Such as serves pages to other remote computers.

WEP

Wired Equivalent Privacy, an encryption system used to prevent wiretap on wireless network traffic. It allows network devices exchange encoded messages with each other privately by using WEP keys.

WPA-PSK

Wi-Fi Protected AccessPre-Shared Key, a wireless encryption method by using pre-shared key.The keys can be manual hex values or hexadecimal characters.

W-LAN

Wireless Local Area Network, a LAN that is connected via a wireless connection.

Zoom lens

A compound lens that remains in focus as the image size is varied continuously. May be motorized or manually operated.

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