名词解释
ActiveX is a framework for defining reusable software components (known as controls) that perform a particular function or a set of functions in a way that is independent of the programming language used to implement them.
In alternating current (AC, also ac) the movement (or flow) of electric charge periodically reverses direction. An electric charge would for instance move forward, then backward, then forward, then backward, over and over again. Refers from Wikipedia.
An ability by which the camera lens automatically adjusts its focus on the captured subject.
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.
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.
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.
A conventional surveillance camera without USB or Ethernet connectivity. Analog surveillance cameras typically output analog composite video signals over coaxial cable.
Analog video output enables installers to monitor the camera output on a conventional video monitor. It's ideal for pointing the camera, setting the focal length and adjusting for lighting conditions.
A kind of iris, is used to adjust the amount of enter light, electrically controlled by the camera.
Is the number of bits that are conveyed or processed per unit of time, often in conjunction with Kbit/s or Mbit/s.
This feature conveys real-time audio between an IP camera and the central office. This enables an attendant in the central office to have a conversation with a person at the camera location. The system requires microphones in both locations and an amplified speaker at the camera position. The G.711 and G.726 compression standards preserve network bandwidth, enabling telephone-quality audio at very modest bit rates.
A storage method 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.
BrickOne Solution: A total-solution service proposed by Brickcom. In addition to the traditional Ethernet cabling that brings together all the IP surveillance components (camera, NVR, CMS, etc), Brickcom provides a full series of network connectivity products (ex. Wi-Fi, 3G, WiMAX, PLC) as well as consulting service that help the client design the system easily, flexibly and beyond the Ethernet cabling's constraints. The client benefits from the one-stop shopping and fully-tailored customization service brought by BrickOne solution.
Complementary Metal-Oxide Semiconductor, one type of image sensor found in digital cameras.
A codec is a device or computer program capable of encoding and/or decoding a digital data stream or signal. Codec convert audio analog to digital and then computer digital sound back to audio.
An industry standard of lens on a camera.
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.
Abbreviation of "Closed-Circuit Television" A television system in which video signals are sent only to monitors in a specific area (e.g. a building) Also called "video surveillance"
Common Gateway Interface, A set of rules that describe how a web server communicates with other (CGI) programs.
Common Intermediate Format, a video format used in analog video. The resolutions are 352x288 pixels for PAL and 352x240 pixels for NTSC.s
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.
Direct Current is the type of electricity. All of the electric charges move in one direction.
The ability of an IP camera to generate two streams of images simultaneously.
The camera with this feature will automatically detect the level of ambient light and instantly adjusts the brightness by switching to Infra-Red (IR) black and white mode.
Dynamic Domain Name Service is a method, protocol, or network service that provides the capability for a networked device.
Dynamic Host Configuration Protocol (DHCP) is a network application protocol used to automatically assign a dynamic IP addresses to individual devices on a network.
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.
To trigger an output alarm, The Network Camera will show whether the trigger is activated or not.
Domain Name System is the internet system to translate names into IP addresses.
Ethernet is a family of frame-based computer networking technologies for local area networks (LANs).
Brickcom Corporation has designed an EasyLink™ feature which offers a unique and easy solution for remotely accessing IP cameras. Requiring no networking or port forwarding configuration, EasyLink™ allows users to assign a unique domain name to their IP camera which can be accessed from virtually any location worldwide.
The video compression is a crucial factor for surveillance industry, Brickcom - Enhanced Variable Bitrate technology aims to provide a superior bandiwdth solution for users to control and manage the bandwidth consumption.
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.
eSATA (e standing for external) provides a variant of SATA meant for external connectivity. It uses a more robust connector, longer shielded cables, and stricter (but backward-compatible) electrical standards.
The original setting from the factory. Resetting the system could set the system back to normal state.
FocusEasy™ is a unique and innovative technology which makes focusing a camera easier, faster, and all by yourself! FocusEasy™ allows the installer to simply rely on his/her hearing to get this task done quickly and perfectly. With 3 simple steps, even a first-time user can focus the camera in 1 minute with the help of FocusEasy™.
The distance between a lens and its focal point; it usually expressed in millimeters. A system with a shorter focal length has wider fields-of-view.
A communications system between two points that supports simultaneous, two-way transmission. For example, a full duplex telephone connection would enable both parties to speak and be heard simultaneously.
The size of apecture, such as F1.2, F1.4.
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.
The rate at which video frames are displayed on a monitor per second.
File Transfer Protocol (FTP) is a standard network protocol used to exchange and manipulate files over an Internet Protocol computer network.
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.
Graphics Interchange Format, a standard format for compression of images. GIF is commonly used on the web because it employs an efficient compression method.
An extension of the MPEG-4 family of compression standards that takes advantage of more recent technology to achieve higher compression "efficiency."
Hypertext Transfer Protocol; is a request/response protocol between clients and servers.
A communications system between two points that only allows one-way transmission at any given time. For example, a half duplex telephone connection would only allow one party to speak at a time, requiring the other to wait.
A video system with up to six times the detail of standard definition. High definition uses a wide, 16:9 aspect ratio screen and a resolution of either 1920 x 1080 or 1280 x 720.
Short for Hypertext Transport Protocol Secure, a method of protecting network traffic from unauthorized access by means of encryption.
High Efficiency Video Coding, is a video compression standard, one of several potential successors to the widely used AVC (H.264 or MPEG-4 Part 10)
IP (Internet Protocol)Internet Protocol; is the main network layer protocol used on the Internet. It defines how information gets passed between systems across the Internet.
A set of security rules that discard IP datagrams or permit them to pass. Filtering enables Sony IP cameras to restrict access to selected IP addresses only.
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.
In IPv4 it is possible to send data to all possible destinations ("all-hosts broadcast"), which permits the sender to send the data only once, and all receivers receive a copy of it. In the IPv4 protocol, the address 255.255.255.255 is used for local broadcast. Refer from Wikipedia.
That is a method of sending Internet Protocol datagrams to a group of interested receivers in a single transmission. It is often employed for streaming media application on the Internet and private networks. Refer from Wikipedia.
It normally refers to a single sender or a single receiver, and can be used for both sending and receiving. Usually, a unicast address is associated with a single device or host. Refer from Wikipedia.
A group of standard wireless specifications developed by the IEEE. It defines a wireless interface between devices to manage packet traffic and supports speeds up to 2Mbps.
The extension of 802.11, the wireless throughput boosts from the original 2Mbps of 802.11 up to 11Mbps.
The extension of 802.11b, it brings wireless throughput up to 54Mbps.
An image sensor is a device that converts an optical image to an electric signal. It is used mostly in digital camera and other imaging devices. Currently a modern one is typically a charge-coupled device (CCD) or a complementary metal–oxide–semiconductor (CMOS). Refers from Wikipedia.
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.
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.
The circular aperture that controls the amount of light passing through to the camera's sensing element.
i-Stream technology aims to reduce the bandwidth consumption when transmitting data but still keep the important details for the consumers. Users can define numbers of region of interest and the system will automatically calculate the most suitable bitrate allocation for the interest areas and non-interest background.
Brickcom i-Mode technology aims to build an easy-to-use platform for users to select the appropriate mode efficiently even the user never use the IP camera before. Brickcom collects various different environment’s specific factors to set up the suitable parameter for each scenario and save in the camera for default, user can select the proper scene mode based on their needs, it just take 3 seconds to finish the camera setting. With Brickcom i-Mode technology, users significantly simplify the installation and reduce the labor time to a minimum.
IR-Cut Filter Removable is a mechanical shutter design. It is placed between the lens and the image sensor and is controlled by a motor or an electromagnet. When the ICR is switched on, it will block iffrared light and allow only visible light to pass throuth.
Abbreviation of "Joint Photographic Expert Group", a process used to compress and store image.
With JBOD (just a bunch of disks), it is possible to concatenate disks, but also volumes such as RAID sets. With larger drive capacities, write and rebuilding time may increase dramatically.
Abbreviation of "Kilobits per second", a unit of measurement for the speed at which data is transported via a communications connection.
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.
A lens is a device, usually made up by a piece of shaped glass. It is used to concentrating or diverging light.
Light Emitting Diode, a semiconductor used to convert information from electrical to optical form, typically as an indicator light.
A measure of visible light intensity taken at the surface that the light source is illuminating. (1 lux = 1 lumen/square meter)
Long-Term Evolution (LTE) is a standard for high-speed wireless communication for mobile phones and data terminals, based on the GSM/EDGE and UMTS/HSPA technologies.
A megapixel (MP) is 1 million pixels, and is a term used not only for the number of pixels in an image, but also to express the number of image sensor elements of digital cameras or the number of display elements of digital displays.
MPEG4 is a video and audio compression technology found in many IP network camera models. The MPEG4 compression standard aims to deliver superior image quality while optimizing bandwidth.
Media Access Control address (MAC address) is a unique identifier assigned to most network adapters or network interface cards (NICs) by the manufacturer for identification.
Megabits per second, a unit for network connection speed.
Megabytes per second, a unit for network connection speed.
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.
MPEG refers to a set of standards for audio and video compression. The acronym MPEG stands for Moving Pictures Expert Group, a group formed by ISO to set these compression standards. Each compression standard is designed for a different purpose.
In terms of IP-based surveillance, motion detection is a network camera application that allows users to trigger events such as recording, high-quality video streaming, and automated alerts to occur only when motion is perceived. Motion detection helps to optimize bandwidth and preserve storage space.
Any number of computers that are connected with one another via different lines and share data and devices.
Network Time Protocol, an Internet standard protocol used for synchronize the network device clock.
A Network Video Recorder (NVR) is a hardware box that receives video streams over a LAN or WAN and captures them onto hard disk in digital format. Recording and playback can be managed remotely using a PC.
OpenVPN is an open-source software application that implements virtual private network (VPN) techniques for creating secure point-to-point or site-to-site connections in routed or bridged configurations and remote access facilities.
Power over Ethernet describes a system to safely transfer electrical power, along with data, to remote devices over standard in an Ethernet network. It does not require modification of existing Ethernet cabling infrastructure.
IP cameras with panning capabilities can move back and forth horizontally in order to monitor wider areas. In many cases a camera's panning functionality can be controlled remotely from a PC using video management software.
Point-to-Point Protocol over Ethernet, is a protocol for network devices to communicate by establishing a DSL link connection with the ISP.
That is an electronic device that measures infrared (IR) light radiating from objects in its field of view. PIR sensors are often used in the construction of PIR-based motion detectors. Apparent motion is detected when an infrared source with one temperature, such as a human, passes in front of an infrared source with another temperature, such as a wall. The term passive in this instance means that the PIR device does not emit an infrared beam but merely passively accepts incoming infrared radiation. Refer from Wikipedia.
With Power over Ethernet, a network device, such as an IP camera, receives power and transmits video and data over a single Ethernet cable. This allows for flexible installation in locations where power outlets aren't readily available.
In computing, a protocol is a set of rules which is used by computers to communicate with each other across a network. A protocol is a convention or standard that controls or enables the connection, communication, and data transfer between computing endpoints. Refer from Wikipedia.
PTZ (pan/tilt/zoom functionality) is a feature available in many IP camera models. PTZ allows users to monitor large areas with a single network camera. Pan, tilt, and zoom functions can be controlled remotely so operators can follow activity and focus in on specific details.
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.
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.
Short for Redundant Array of Independent Disks. A storage system that protects valuable data from hard disk crashes. Because RAID redundancy places data bits on multiple drives, data can survive even if a drive fails. For redundancy, you need RAID level 1 and higher.
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.
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.
A region of interest (often abbreviated ROI), are samples within an data set identified for a particular purpose.
RAID 0 consists of striping, without mirroring or parity. The capacity of a RAID 0 volume is the sum of the capacities of the disks in the set, the same as with a spanned volume. There is no added redundancy for handling disk failures, just as with a spanned volume.
RAID 1 consists of data mirroring, without parity or striping. Data is written identically to two drives, thereby producing a "mirrored set" of drives. Thus, any read request can be serviced by any drive in the set.
RAID 5 consists of block-level striping with distributed parity. Unlike RAID 4, parity information is distributed among the drives, requiring all drives but one to be present to operate. Upon failure of a single drive, subsequent reads can be calculated from the distributed parity such that no data is lost. RAID 5 requires at least three disks.
RAID 6 consists of block-level striping with double distributed parity. Double parity provides fault tolerance up to two failed drives. This makes larger RAID groups more practical, especially for high-availability systems, as large-capacity drives take longer to restore. RAID 6 requires a minimum of four disks.
creates a striped set from a series of mirrored drives. The array can sustain multiple drive losses so long as no mirror loses all its drives.
Sharpness describes the clarity of detail in a image.
A measurement of chrominance, or the intensity of color in the video signal.
Samba provides file and print services for various Microsoft Windows clients and can integrate with a Windows Server domain.
Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (e-mail) transmission across Internet Protocol (IP) networks. SMTP is specified for outgoing mail transport and uses TCP port 25. Refer from Wikipedia.
SmartFocus® is a special Brickcom camera feature which works with the motorized lens module, but focuses the image just once and is aimed at speeding up the installation. SmartFocus® focuses the image automatically just once, and then stays at the point until the next time the user does the optical zoom-in/zoom-out. The technology allows the users to be able to focus the camera from their computer without having to physically go to the camera location site.
S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology; often written as SMART) is a monitoring system included in computer hard disk drives (HDDs) and solid-state drives (SSDs) that detects and reports on various indicators of drive reliability, with the intent of enabling the anticipation of hardware failures.
TCP enables two hosts to establish a connection and exchange streams of data. It guarantees that packets will be delivered in the same order in which they were sent.
Tilt refers to an IP camera's ability to be directed up and down in a vertical plane. The camera lens can be aimed at a specific part of a scene, and in many cases the tilt can be controlled remotely.
The User Datagram Protocol (UDP) is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. UDP uses a simple transmission model without implicit hand-shaking dialogues for guaranteeing reliability, ordering, or data integrity. Thus, UDP provides an unreliable service and datagrams may arrive out of order, appear duplicated, or go missing without notice.
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.
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.
Uninterruptible Power Supply is an electrical apparatus that provides emergency power to a load when the input power source or mains power fails.
To completely avoid the camera from external impact and make it ideal for video surveillance outdoors.
It refers to reducing the quantity of data used to represent digital video images, and is a combination of spatial image compression and temporal motion compression.
Stands for Video Graphics Array, a computer display resolution which standard of 640 x 480 pixels. See also XGA, SXGA, UXGA, and WXGA.
A program that retrieves and is able to display data from another computer HTML is the data language used to transmit data.
In IP surveillance, connection methods that make it possible to install cameras in parking lots and other locations beyond the reach of Ethernet cables. Wireless technologies include 802.11 and WiMax.
Abbreviation of "Wireless Local Area Network".
Wi-Fi Protected Setup (WPS) is a standard for easy and secure establishment of a wireless home network, created by the Wi-Fi Alliance and officially launched on January 8, 2007. The standard achieves its goal by putting much emphasis into usability and security, and the concept is implemented through four usage models that enable a user to establish a home network.
Short for Wide eXtended Graphics Array, a widescreen computer display resolution standard of 1280 x 800 pixels.
Short for Worldwide Interoperability for Microwave Access, a broadband wireless communications standard. WiMax enables high-speed communication both for corporate networks and for wireless carrier networks.