Classification of security surveillance cameras

Classification of security surveillance cameras

Based on our experience, combined with the classification standards of industry leaders such as Hikvision, Dahua, Uniview, and Axis, the following is summarized:

1. Video Output Signal

For security cameras, the video output signal is when light passes through the lens and hits the image sensor inside the camera . At this time, it is still an analog signal. It is converted into a digital signal through A/D, processed by ISP or DSP, and then output as a video signal.

Before output, if it undergoes D/A conversion again, that is, the digital signal is converted into analog signal output, this camera is generally called an analog camera. Common ones include cvbs analog standard definition cameras (basically eliminated), XVI/TVI/CVI/AHD and other high-definition analog cameras.

If the direct output is a digital signal, it is called a digital camera. For example, an SDI camera is a digital camera that is often used in video conferencing. According to the transmission rate, SDI can be divided into SD-SDI, HD-SDI and 3G-SDI. The SDI cameras generally used for security are HD-SDI or 3G-SDI.

In the third case, in order to reduce the amount of transmitted data, the digital signal is encoded and compressed according to a certain method standard (such as H.264, H.265, H.266) and then output. This type of camera is called a network camera.

2. Appearance

According to the shell of the camera, it can be divided into gun camera, barrel camera, hemispherical camera, ball camera, pan/tilt camera, etc.

The so-called gun camera, also called box camera, looks like a box, can be equipped with C/CS interface lens, does not have additional fill light, and the various interfaces of the camera are generally at the rear. If installed in an outdoor environment, this camera needs to be equipped with a protective cover.

The barrel camera generally refers to an infrared gun-type camera, lens, infrared or white light fill light, and the camera itself. The appearance can reach the protection level of IP66 and IP67. The various interfaces of the camera are connected through the tail wire at the end, and it is often used in outdoor environments. It is suitable for wall mounting or hanging mounting. Some barrel cameras come with mounting brackets.

Some installation environments, such as ceilings, are not suitable for the installation of gun-type and barrel-type cameras. In this case, a dome camera is needed to facilitate ceiling or embedded installation on the ceiling. The internal structure and functions of the dome camera are exactly the same as those of the barrel camera.

The camera, the pan/tilt that controls the camera's up and down rotation, and the additional fill light are combined and stuffed into a spherical shell. This type of camera is generally called a dome camera. In addition to the functions of a general camera, a dome camera also supports PTZ, i.e. horizontal rotation (Pan), vertical rotation (Tilt), lens zoom, focus (Zoom) and other functions to achieve 360-degree all-round, long-distance and no-dead-angle monitoring. The dome camera can be equipped with different mounting brackets to support wall mounting, ceiling mounting or embedded mounting.

If the camera with PTZ function does not have an additional ball protection cover, the camera is directly placed on the PT platform. This kind of camera is called a PTZ camera. Except for the appearance, it is completely the same as the ball camera. The advantage of this appearance of the camera is that it is easy to place on a horizontal platform, such as the roof of a car, various operating tables.

3. Pixels/resolution

Whether it is a network, analog, or digital camera, it can be classified according to the pixels and resolutions it supports, ranging from standard definition cameras with hundreds of megapixels to high-definition cameras with 12 million 4K resolution.

For general standard definition cameras, if they are analog, we directly call them cvbs or 960H cameras, not directly named by pixels. If they are network cameras, they are directly called standard definition or SD cameras. 720 resolution, above one million pixels are directly named by pixels/resolution. For example, 1 million, 2 million, 3 million, 5 million, 8 million, 12 million. If named by resolution, it is 720P, 1080P, 4K, or HD, FHD, UHD.

4. Light

The camera produces color images during the day, but needs a fill light to produce images at night when the ambient light is very weak or in a completely dark environment. Of course, some cameras, such as starlight-level cameras, can still produce color video images as long as there is weak light. Depending on whether an additional fill light is needed, the camera can be divided into infrared cameras (which can be divided into 850nm infrared and 940nm infrared), white light fill light/warm light cameras, and starlight full-color cameras.

5. Special Purpose

In some occasions and environments prone to explosions, such as refineries, pipeline gas transportation, oil and gas exploration, mining, etc., as well as oceans, ships and other highly corrosive environments such as salt, acid and alkali, cameras made of special appearance materials are needed to prevent explosion and corrosion.

6.Fields of use

With the development of chip technology, software technology, network technology, etc., security cameras have gradually moved from professional fields to the general civilian market, and more and more home WiFi cameras have entered thousands of households. According to different fields of use, security cameras can be divided into professional fields and ordinary home use. Ordinary home cameras mainly support WiFi networking, TF card or cloud storage, simple AI functions (such as human detection, voice alarm, etc.), mobile phone APP management, etc.

7. Special scenarios

We need to select cameras with different functions for different scenes and monitoring purposes. For example, for parking lots, license plate recognition cameras are needed. For intelligent transportation, cameras with functions such as illegal capture, license plate recognition, and traffic flow statistics are needed. There are also industrial cameras that support machine recognition, cameras that support face counting, cameras for video conferencing, thermal imaging cameras, cameras that support wide dynamic range/strong light suppression, mini/pinhole cameras used in special occasions (such as bank ATMs), and wearable cameras for mobile law enforcement.

8. Video output interface

Cameras can be divided into these types according to the different video signal output interfaces.

• The BNC interface
is mainly used for analog cameras, such as cvbs/960H, AHD/CVI/TVI/XVI, etc. SDI cameras also generally use BNC connectors to output digital signals.

• RJ45 network port
is generally a network camera.

• HDMI
digital cameras, such as SDI cameras, can directly output video signals through HDMI. Network cameras can also directly output digital video signals through HDMI before encoding.

• The serial port
outputs the video signal through the serial port, such as RS-485, 232, TTL interface. Generally, this type of camera is used to connect with other hardware devices, such as industrial control, electricity, water conservancy and environmental monitoring equipment, law enforcement evidence collection equipment, etc.

• USB
USB interface cameras are actually a type of serial port cameras. They are classified separately here to refer to cameras that are connected to computers via USB interfaces and can capture video images in computer software. They can generally be used for video chat and video conferencing functions on computer software.

• Fiber-optic
network cameras, with fiber-optic interfaces, transmit video signals via optical fibers, eliminating the need for additional configuration of fiber-optic transceivers.

• Aviation connector
This type of camera is mainly used in vehicles. Various lines such as video and power are gathered together to form an independent interface, which is easy to plug and unplug, stable and reliable.

9. Lenses

Based on the type of lens used, the number of lenses can be used to categorize security cameras as follows:

Of course, according to the aperture of the lens, it can also be divided into fixed aperture lens, manual aperture lens, automatic aperture lens. Automatic aperture can also be divided into DC drive aperture lens, video drive aperture lens, P-iris lens, i-CS lens, etc.

10. Signal Transmission

According to the transmission method and transmission medium used, security cameras can be divided into coaxial video line transmission, twisted pair transmission, power line transmission, optical fiber transmission, WiFi transmission, 4G transmission, etc.

It should be noted that with the help of some conversion transmission equipment, such as coaxial network transmitter, the coaxial video cable can be used to transmit the signal of the network camera. Similarly, with the help of twisted pair transmitter, a pair of 2 twisted wires can be used to transmit the signal of the analog camera. With the help of the corresponding power line transmitter, the network camera signal or the analog camera signal can be transmitted through the power line.

11. Powered

Cameras use different power sources, commonly used are AC24, DC12, DC5V, etc. Depending on the different power sources used, you can also configure solar energy or batteries, 18650 batteries, etc. to power the camera.

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