HC Security Network News Network Camera has now become very popular, which relate to the common saying many people do not understand, we come to know today about the security network cameras professional and technical terms to explain it.

Resolution: Divided into display resolution and image resolution. Image resolution refers to the number of pixels contained in a unit of inch. The display resolution refers to the precision of the screen image, and refers to how many pixels the display can display. Since the dots, lines and faces on the screen are composed of pixels, the more pixels the display can display, the finer the picture, and the more information that can be displayed in the same screen area, so the resolution is a very important performance. One of the indicators.

Primary stream/substream: The primary stream is used for local storage and the substream is suitable for images to be transmitted over low bandwidth networks. The dual stream uses a high bit rate stream for local HD storage, such as CIF/D1 encoding, and a low bit rate stream for network transmission, such as QCIF/CIF encoding, while taking into account local storage and remote network transmission.

Composite stream/video stream: The composite stream synchronously transmits audio and video; the video stream only transmits video.

Variable code rate/fixed code rate: The variable code rate is also the non-fixed bit rate. The audio coding software instantly determines which bit rate to use according to the complexity of the audio data during encoding. This is based on the quality and the file size. The size of the fixed bit rate FRAME is also fixed. A fixed compression coded value is used from start to finish.

Motion detection: The image acquired by the camera will be calculated and compared by the CPU according to a certain algorithm. The result is instructed to automatically process the corresponding processing. When the picture changes, if someone walks through, the lens is moved, etc., and the corresponding result will be generated.

PIR Human Induction: (PassiveInfraredDetection) Passive infrared detector or body sensor. People are warm-blooded animals, and infrared radiation is also the most stable. We call the PIR detector a passive infrared detector because the detector itself does not emit any energy and only passively receives and detects infrared radiation from the environment. When the infrared radiation of the human body comes in, the focus of the optical system causes the pyroelectric device to generate a sudden electrical signal, thereby issuing an alarm. Passive infrared intrusion detectors form a warning line that can typically reach tens of meters.

Activity detection reminder: Adding PIR human body sensing factor based on motion detection, that is, combining two conditions at the same time will trigger the alarm. Reduce false alarms such as curtains and leaves under certain conditions.

Occlusion alarm: As the name suggests, the camera or camera cover is blocked by dust or artificially malicious, resulting in the video image quality falling to an indistinguishable degree. The program in the camera promptly makes an alarm reminder through the algorithm. Note: There is no video linkage for this alarm.

Cross-border detection: The perimeter is detected by setting a virtual fence. When a suspicious person or object is found to cross the fence, an alarm is triggered.

Applicable in: traffic road crosswalk or zebra crossing; fence in key areas of the factory; school; fence wall of detention center.

Area Intrusion Detection: By setting a certain area (can be set to any shape) as the warning state on the screen, when an object illegally enters the warning area, an alarm is triggered and the intrusion object is analyzed at the same time. For example, when someone enters the warning zone, an alarm is illegally broken into the restricted area; when a car enters the warning zone, an illegal vehicle is found to enter the restricted area.

Applicable in: some key protected areas such as bank vaults, scenic spots; vulnerable areas; military restricted areas; museums; docks; hospitals, etc.

White balance: The image taken in the room of the fluorescent lamp will appear green, the scene taken under the indoor tungsten light will be yellowish, and the photo taken in the sunlight shadow will be inexplicably blue, the reason is "White balance" setting. White balance, the most popular understanding is that the image made by white is still white. If white is white, the image of other scenes will be close to the color vision habit of the human eye. Digital wide dynamics: In the backlight environment, the details of the dark areas can be clearly preserved and the exposure is suppressed, which greatly improves the image quality of the backlight scene.

3D noise reduction: make the night monitoring picture noise small, the picture quality is smooth and smooth.

SMARTIR: Intelligent image processing technology is used to intelligently adjust the brightness curve by detecting the multi-block brightness of the image, thereby preventing the over-exposure of a certain block image and the underexposure of a certain block image. It can solve the problem of over-exposure of close-range infrared lamps.

Timed recording: manually set a fixed time. When this setting is enabled, the video in the time period will be automatically stored, which is video recording. Divided into all-day video, time period video.

1/3": Strictly speaking, it is the specification of the photosensitive element, which refers to the area of ​​CCD/COMS. The larger the area, the more the CCD/COMS photosensitive point, the higher the pixel of CCD/COMS itself, the other conditions are the same. In the case of the output, the picture will be clearer.

1/3 inch - the target size is 4.8mm wide by 3.6mm high and 6mm diagonal.

1/4 inch - the target size is 3.2mm wide by 2.4mm high and 4mm diagonal.

Time-lapse shooting: Time-lapse shooting refers to taking pictures every other fixed time; then playing the picture in a short time, showing a strange and wonderful scene that is usually undetectable by the naked eye.

Network part

Router/switch: Interface, there is no essential difference, it is RJ-45 interface, but the router has a distinction between LAN port and WAN port relative to the switch, but the switch does not. Function, the router is a switch-containing function relative to the switch, and the switch is often used to extend the network interface.

The router implements the switch function: the network cable coming out of the cat should not be plugged into the WAN port, but inserted into the DHCP function of any LAN port to close the route.

DHCP: (DynamicHostConfigurationProtocol) is a LAN network protocol. The main function is to centrally manage and assign IP addresses, so that hosts in the network environment can obtain information such as IP addresses, Gateway addresses, and DNS server addresses dynamically, and can improve the usage rate of addresses.

UPNP: UPnP protocol is universal plug and play English is UniversalPlugandPlay, abbreviated as UPnP. The UPnP specification is based on the TCP/IP protocol and a new Internet protocol for communication between devices.

MAC address: (MediaAccessControl or MediumAccessControl) address, which is translated as media access control, or physical address, hardware address, used to define the location of the network device. The image says that the MAC address is like the ID number on our ID card and is unique. The physical address of the network card is usually the EPROM burned into the network card by the network card manufacturer (a kind of flash memory chip, which can usually be erased by program). It stores the computer that actually transmits the data and the host that receives the data when transmitting the data. address.

MAC address binding: Since each network adapter card has a unique MAC address, in order to prevent illegal users from stealing network resources, MAC address binding can effectively avoid illegal user access. For the security protection of the network physical level.

Editor in charge: Zhang Zequn