Difference between revisions of "Terminology"

Revision as of 19:13, 7 December 2015

960H

960H is a new video standard for security systems that provides high resolution images using new advanced image sensors. Security cameras capable of 960H produce an image that is 960x480 compared to 702x480 for D1 and 352x240 for CIF.

ACCESS CONTROL

The ability of restriction access to certain areas.

Aperture

Controls how much light can go through the lens and sensor.

ATM

Automated teller machine

POS

Point of Sale

Bitrate

Byte transfer speed for every second it transfers. The unit is bps(bit per second).The higher the bitrate is, the more data it can transfer.

Blind zone

The area which is not detected in the image.

Constants Bit Rate

CBR

Fixed sample rate compression. The advantage is fast compression, can be supported by most software and device, the disadvantage is the relatively large space

DDNS

A method of automatically updating a name server in the Domain Name System (DNS), often in Not Real Time, with the active DDNS configuration of its configured host names, addresses or other information. The term is used to describe two different concepts.

DECODE

This is a device, circuit, program, algorithm the would covert information from one media format to another. This would be the purpose of standardization, speed secrecy or comparison. The input signal to a video decoder is analog video that conforms to a standard format such as NTSC or PAL.

Definition of Internet

Wikipedia - The Internet is a large group of computers that are connected to each other. The Internet is used to send information quickly between computers around the world. It has millions of smaller domestic,academic, business, and government networks and websites, which together carry many different kinds of information (facts and details) and services. So in other words, the Internet is a network of networks.

Detection area

The area which is needed to be detected in the image.

Distance of network cable

We use the fiber to connect the countries. We only use network cable when it reaches to final clients. So it mainly depends on the fiber to communicate.

DOF calibration

rebuild environment 3-D information.

EIS

Electronic image stabilization-ensures image is clear even if the camera is moving.

ENCODER

this is a device, circuit, program, alogorithm the would covert information from one media format to another. This would be the purpose of standarization, speed secrecy or comparision.

EXTRA STREAM

This is the secondary or third video output stream for access the DVR/NVR/IP Camera system from a remote location.

Failed alarm

it meets the rule condition but fails to trigger alarm.

False alarm

False alarm caused by interference source (light change, leaf waggling, rain & snow, small animals)

Field of view

The overall image displayed by the camera.

FTP

Termed as File transfer protocol, it is a network protocol for transfering files from one point to another over the TCP based network, ie: the internet.

H.264

The intent of the H.264/AVC project is to create a standard capable of providing good video quality at substantially lower bit rates than previous standards, without increasing the complexity of design so much that it would be impractical or excessively expensive to implement.

HDCVI

In November 2012, Dahua technology released analog high-definition transmission interface technology-HDCVI（High Definition Composite Video Interface）, with self-owned intellectual property right. HDCVI technology is a HD video transmission method, based on existing RG-59 or RG-6 coaxial cable. It can achieve long distance HD video signal reliable transmission at low cost via low general coaxial cable. In the practical application, HD-SDI subsystem requires high transmission medium, while HDCVI is suitable to the long distance, low cost transmission medium and complex deployment situation.

HEVC

H.265

Also known as High Efficiency Video Coding.

HDD

Also known as Hard Disk Drive, it is a device that would store files like documents or in our case video recorded files as a digital file.

I Frame Interval

the interval time between every two I frame, I-frame is called intra-picture, P-frame is called prediction picture. I-frame need more space and the best image quality.

IP Cam (Network Camera)

IPC

IP Camera

Network Camera

An Internet protocol camera, or IP camera, is a type of digital video camera commonly employed for surveillance, and which, unlike analog closed circuit television (CCTV) cameras, can send and receive data via a computer network and the Internet.

IR LEDs

Illuminates image in the night. Infrared light emitted by the light, wavelength of 850nm and 940nm, are not visible , energy saving, the past 10 years, it has been widely used in the field of security monitoring

IVS

Intelligent Video Surveillance-Estimate the camera’s internal parameters (including internal geometric features, optical features) and external parameters (the camera’s 3D location and direction relative to the real coordinate system) according to one horizontal line and three altitude lines calibrated by users, then confirm the corresponding relations between the 2D image captured by the camera and real 3D object.

LAN

Local Area Network

A local area network (LAN) is a group of computers and associated devices that share a common communications line or wireless link. For example, an enterprise network is generally a local area network. A network of large-scale video surveillance project is a local area network.

MAC Address

MAC is the ID of the computer. Each computer has its own identity. It is unique around the world. The Mac address is binding with the device once it is produced. Usually we do not modify it. Of course, we can use COM to change its setup.

MAIN STREAM

This is the main video output stream feeds for the camera or channels that is for a local remote use, meaning within network.

Minumum Illumination

Min Illumination

Minimum illumination is a parameter to show the camera‘s performance in the night or low light scene. The smaller the value is ,the higher the sensitivity of the sensor is.

MJPEG

M-JPEG

Motion JPEG

Motion JPEG (M-JPEG or MJPEG) is a video compression format in which each video frame or interlaced field of a digital video sequence is compressed separately as a JPEG image.

Multicast

It is to allow the NVR/DVR to work more efficently by steaming one access feed and letting the Router device distribute the video feed to multiple devices.

ONVIF

A global and open industry forum with the goal to facilitate the development and use of a global open standard for the interface of physical IP-based security products. Or in other words, to create a standard for how IP products within video surveillance and other physical security areas can communicate with each other

ONVIF/PSIA

PSIA

These protocol regulate the function of application interface. By these protocol, not only DAHUA IPC could be accessed to DAHUA NVR, but also others brands that support ONVIF or PSIA. And all over network devices, which support ONVIF or PSIA, could communicate each other.

P2P

Is a network point to point access without compromising the Router or modem's firewall.

Power over Ethernet

POE

Power over Ethernet. By this technology, we could transmit the network signal not only with single cable, but also the power supply. (MAX. Distance 100 Meter)

PreRecord

Pre-Record

You can set pre-record time(from 1-30s), this function can extend the life of HDDs and help to analysis MD/Alarm video( you can refer the event part )

PTZ

An acronym for Pan Tilt and Zoom.

Resolution

The resolution of a camera is often limited by the image sensor that turns light into discrete signals. The brighter the image at a given point on the sensor, the larger the value that is read for that pixel.

ROI

Region of Interest- allows cameras to enhance image quality of region of interest by decreasing non-ROI’s image quality to acquire more computing power and bandwidth.

RTSP

Real time Streaming Protocol is a network protocol that was designed for the use in Entertainment and Video Communication systems to control the video servers. The use was for the establishment and controling media sessions between the two points.

Sensitivity

The difficulty level of target detection and alarm, the higher the sensitivity is, the easier it is to detect, but with more false alarms; the lower the sensitivity is, the less false alarm will be, but with more failed alarms.

Size filter

Only reserve the target which meets the requirement of size (width height/area) and aspect ratio.

Smart detection

tripwire, intrusion detection, abandoned/missing, scene change, defocus, facial detection and audio detection, allowing automatically detect under rulemaking and trigger alarms, accordingly.

SUB STREAM

This is the secondary or third video output stream for access the DVR/NVR/IP Camera system from a remote location.

Target

Moving object with some certain type (such as human, vehicle and etc.) which appears in the field.

TCP/UDP

TCP

UDP

These protocol regulate the transmission method of network signal of IP equipments. By these protocol, we realized our DAHUA IPC to access our DAHUA NVR, and all over the DAHUA network devices could communicate each other.

Tripwire Function

Only applied to the scene where the targets are sparse and there is rarely any covering between targets, such as the perimeter without any guard. It will trigger alarm when the target passes through the warning line according to the set movement direction. It takes some time from the target appears to the target is confirmed, so it needs to leave some space when setting warning line, do not set it near the covering. Detect if there is any object crossing the warning line, it can support different direction selection, such as A->B, B->A and bidirectional, and it can activate record , snapshot and alarm according to the judgment result.

Variable Bit Rate

VBR

without a fixed bit rate, in the compression software, determined by the instant video data bit rate, quality taking into account.