Recently, many readers who have just entered the industry have reported that they want to have the latest video surveillance terminology documents. Therefore, based on the existing content of the security knowledge network, the author combined some common foreign video surveillance terms to organize this part to help professionals quickly understand the surveillance industry. Due to a large amount of workload of sorting, the content will be updated from time to time. At the same time, mistakes will inevitably occur during the process. If you have any questions, please contact us in time.
AHD: It is a reliable transmission technology for high-definition video signals. AHD technology achieves reliable transmission of ultra-long (500 meters) high-definition video signals on existing analog transmission lines. It adopts advanced Y/C signal separation and analog filtering technology, which can effectively reduce the color noise in high-frequency areas. Also, it has better image restoration.
ANPR: Automatic Number Plate Recognition is also called License Plate Recognition (LPR) in some places.
API: Application Programming Interface is predefined interfaces (such as functions, HTTP interfaces) or conventions for the connection of different components of a software system. In video surveillance systems, most APIs are not publicly available. API is often used to achieve system integration with first-party software, such as access control systems, building control systems, fire control systems and environmental monitoring systems.
AoV: Angle of View is often associated with Field of View (FoV).
a&s: It refers to "a&s China", which was founded in 1994 and is the first professional security industry magazine in China.
BLC: Backlight compensation can effectively compensate for the dark defect of the subject of the picture when the camera is shooting in a backlit environment. When the camera is in a backlight environment, there will have a black image. However, the backlight environment is unavoidable in security, so backlight compensation is required. When the backlight compensation function is used, if the camera detects a low video level in an area of the captured image, the AGC circuit can improve and enhance the video level in this area and increase the amplitude of the output video signal and make the whole image clear and bright. If a subject is dimmed due to a bright background, you can set the BLC to ON to compensate for the strong backlight. Simply speaking, in a low-light environment, clear pictures can be obtained with a darker background.
Zoom ratio: The zoom ratio refers to the ratio of the shortest focus to the longest focus of the zoom lens. The zoom ratio cannot fully reflect the zoom level and performance of the camera lens.
CBR: Constants Bit Rate refers to a static (constant) bit rate. CBR is a compression method with a fixed sampling rate. The advantage is that the compression is fast and can be supported by most software and devices. The disadvantage is that it occupies a relatively large space and the effect is not very good. Therefore, it has been gradually replaced by VBR.
CCD: Charge-coupled device indicates the signal size by the amount of charge. It transmits the signal detection element by coupling, and it has advantages such as self-scanning, wide sensing spectral range, small distortion, small size, lightweight, low noise system, low power consumption, long service life, and high reliability. Also, it can be made into highly integrated components. It was previously a common sensor used in cameras, but it has been replaced by CMOS.
CMOS: It stands for Complementary Metal Oxide Semiconductor. Due to the low production cost and excellent performance in low light, wide dynamic, and high resolution, it has become a common sensor type for cameras.
CNN: Convolutional Neural Networks (CNN) is a type of Feedforward Neural network that includes convolutional computation with a deep structure, which is one of the representative algorithms of deep learning.
DoF: Depth of Focus refers to the distance to the front and back of the objective being photographed by a camera lens or other imagers that can obtain a clear image. Aperture, lens, and the distance from the focal plane to the object are important factors that affect the depth of focus.
DHCP: Dynamic Host Configuration Protocol is a LAN network protocol. It refers to a range of IP addresses controlled by the server, and the client can automatically obtain the IP address and subnet mask assigned by the server when logging in to the server. Most IP cameras use DHCP for initial device settings by default.
DNR: Digital Noise Reduction uses digital processing to reduce the impurities in the video signal. Since the image noise is random, the noise in each frame of the image is different. 3D digital noise reduction automatically filters out non-overlapping information (noise) by comparing several frames of adjacent images, thereby displaying pure and delicate pictures.
DVR: Compared with the traditional analog video recorder, Digital Video Recorder (DVR) uses a hard disk video recorder. Therefore, it is often called a hard disk video recorder.
DWDR: Digital overlay wide dynamic range is different from wide dynamic range. Digital overlay wide dynamic range is one of the easiest technology to implement. The wide dynamic range can ensure clear images in most strong light or backlight monitoring environments while digital overlay wide dynamic range can only solve part of picture problems.
EIS: Electric Image Stabilization refers to electronic stabilization technology implemented through a software algorithm.
EOL: End-Of-Life refers to products or projects that have been discontinued.
F-Stop: It refers to the aperture series (or the aperture value: F-number), such as f/1.4, f/2.8, etc. The larger the f/x.x, the smaller the aperture, the less light input, and the slower the speed.
FPS: In general, Frames Per Second refers to the number of animation or video frames transmitted per second. In the field of security, 30FPS is usually called full frame rate, and general video surveillance is between 10 and 25.
FoV: Field of view refers to the range that can be covered by a lens (objects beyond this view will not be contained in the lens). The scope of the scene covered by a camera lens is usually expressed by the view, which is called the FoV of the lens.
GDPR: "General Data Protection Regulation" (GDPR) is a regulation of the European Union, which is formerly known as the "Computer Data Protection Law" enacted by the European Union in 1995. It has influence and regulation on video surveillance data, biometrics, and other applications.
GOP: Group of pictures refers to the distance between two I frames. A group of pictures is formed between two I frames is GOP.
GPU: Graphics processing unit (GPU) is also known as display core, visual processor, and display chip. It is a microprocessor designed to do graphics-related computing work on personal computers, workstations, game consoles and mobile devices (such as tablet computers, smartphones, etc.).
HD-CVI: High Definition Composite Video Interface (CVI) is a high-definition video transmission specification based on coaxial cable, which uses analog modulation technology to transmit progressive scan high-definition video.
HD-TVI: It stands for High Definition Transport Video Interface, which is a high-definition video transmission standard based on coaxial cable. As a new analog high-definition solution, it can solve the existing analog high-definition defects in the market.
HDD: It stands for Hard Disk Drive, which is also known as mechanical hard disk in the industry. It is a commonly used storage medium for monitoring.
HFOV: Horizontal field of view refers to the maximum angle that the camera lens can reach in the horizontal direction.
HLC: Highlight compensation can be used to reduce the stimulation of high light sources (such as car lights and street lights) to human eyes by reducing the fray of the area with the highest brightness in the image.
Aspect ratio: It is also known as screen ratio, which is the ratio of screen width and height. 4:3 and 16:9 are two standard ratios, and 16:9 also has several variants, such as 15:9 and 16:10. In cameras, 16:9 is a common aspect ratio, which is the preferred ratio of high-definition 720P and 1080P sensors. Also, 4:3 and 3:2 ratios are used in some cameras.
IK: It refers to the IK protection level (0-10), which represents the protection level of the enclosures against the external harmful mechanical impact. The IK standard is applicable to the protection classification of electrical equipment enclosures against external mechanical impact with a rated voltage not exceeding 72.5kV. It is only applicable to enclosures that have special requirements for the protection classification of external mechanical impact.
IP (Ingress Protection): The system is drafted by IEC (INTERNATIONAL ELECTROTECHNICAL COMMISSION), which classifies electrical appliances according to their characteristics of dust and moisture resistance. IP is composed of two numbers. The first number represents the level of dustproof and intrusion prevention of external objectives (including tools and human fingers that are not allowed to touch the live parts to avoid an electric shock). The second number represents the airtight degree of the electrical appliance against moisture and water immersion. The larger the number, the higher the protection level.
IPC: IP Camera is a new generation of cameras that combines traditional cameras and network technology. It can transmit video images to the other side of the world through the network, and the remote browser does not need any professional software, as long as a standard Internet browser (such as Microsoft IE or Netscape) can monitor their video images. In general, the IP camera is composed of a lens, image sensor, sound sensor, signal processor, A/D converter, coding chip, main control chip, network and control interface.
IR: Infrared Radiation is a wireless communication method that can transmit wireless data. In the field of monitoring, it refers to infrared camera technology, which is divided into passive infrared camera technology and active infrared camera technology. Passive infrared camera technology uses the principle that any object above absolute zero (-273°C) emits infrared light. The infrared light emitted by the human body and heating objects is stronger, while the infrared light emitted by other non-heating objects is weak. Therefore, special infrared light can achieve night monitoring. Passive infrared camera technology cannot be used in night vision systems due to the high cost of equipment and the inability to reflect the surrounding environment. The active infrared camera technology uses a special "infrared lamp" to artificially generate infrared radiation that is invisible to the human eye but can be captured by normal cameras to illuminate the scene and the environment. Normal low-illumination CCD black-and-white cameras or cameras that can take colorful videos in the daytime and turn black and white at night or cameras with "infrared low-lightness color" all can feel the infrared light reflected from the surrounding environment, to achieve the night vision function.
LAN: It refers to local area network. In general, the coverage of the local area network is within a few kilometers. It is widely used in all types of offices due to its characteristics of convenient installation,cost-saving, and easy expansion. The local area network can achieve file management, application software sharing, printer sharin,g and other functions. During use, the maintenance of local area network security can effectively protect the security of data and ensure its normal and stable operation.