Video surveillance systems
What are CCTV systems?
Installing a video surveillance system is today an integral component of security for both businesses and residential premises.
The standard set of devices for organizing a video surveillance system is a set of IP cameras -> switch -> IP video recorder / video surveillance server. The last component is selected based on the requirements for the functionality of the system: IP video recorders are primarily designed for storing video recordings and are used to process information from a relatively small number of video surveillance cameras, while video surveillance servers are able to implement action algorithms without human intervention, store much larger archives data and capable of serving hundreds of devices on an IP network.
The choice of each of the elements of the video surveillance system
P-cameras. In recent years, professionals increasingly prefer digital cameras. And this is not surprising, because they significantly outperform analog models in their performance parameters, including signal quality, system scalability and advanced video processing functionality. There are several classifications for IP cameras that you should know before purchasing one or another model:
IP camera classifications
Depending on the location of the camera, there are:
> street. Typically, such models are equipped with special protective thermal housings that protect the camcorder from adverse weather conditions and critical air temperatures. In addition, most outdoor units are powered by an Ethernet cable, eliminating conventional power systems.
>indoors. This type of surveillance cameras is made in a standard housing and is designed for indoor installation. Usually their dimensions are extremely compact, and the appearance of these models is distinguished by its elegance and smooth lines, so as to successfully fit into any interior.
Video quality
by video recording quality (below are the most common resolutions):
>Standard Definition. Based on a 4:3 (sometimes 16:9) aspect ratio, this format outperforms analog broadcasts. SD clarity is characterized by a resolution of 480 x 576.
>high definition. This broadcast format provides a 16:9 aspect ratio and a resolution of 1280 x 720 pixels. HD is characterized by multi-channel audio, usually according to the Dolby Digital standard.
>Full High Definition. This format features improved video playback quality, providing a resolution of 1920 x 1080 pixels and 16:9 aspect ratio.
Form factor
Depending on the form factor of the camera, there are:
> standard. This type of IP camera is characterized by its compactness and the ability to individually adjust the lens (both manual and remote, depending on the model).
> domed. Such models have a unique body design that does not allow intruders to visually determine the direction of the lens and prevents unauthorized dismantling.
> unframed. Unpackaged video surveillance cameras are designed to be built into the wall, thereby preventing the device from being hacked. In addition, this installation option will allow the IP camera to fit into the overall stylistic concept of the room as successfully as possible.
Viewing angle
according to the viewing angle of the camera there are:
> panoramic. Such IP cameras provide the widest possible viewing angle and are excellent for monitoring large-scale areas.
>PTZ cameras. This type of device provides for remote control of zoom, as well as the angle of inclination and rotation of the lens.
> with a limited viewing angle. It is convenient to install such IP cameras to view stairwells, shop windows and any other areas where only a certain area of the room needs to be monitored.
> by the physical size of the matrix. The larger its size, the less noise is formed in the frame. For detailing video surveillance, models with a matrix size of ¼ ”and more are welcome.
Shooting type
according to the type of shooting cameras are:
>usual. Allows you to shoot video in normal lighting conditions. In daylight or artificial light.
>with IR illumination. These IP cameras provide round-the-clock video recording in conditions of complete absence of lighting. At night, thanks to infrared projectors, the recording is done in gray tones. The latest models allow you to shoot in color.
>thermal imaging. Such models allow you to capture what is happening in the frame in conditions of fog, dust, snow, etc. The image is presented in conditional colors, with a gradation from blue to red, depending on the temperature of the object being photographed. Allows you to distinguish between people, animals and objects with a different temperature from the environment.
number of channels.
This is a key characteristic that determines the number of IP cameras that this recorder can display in separate windows of its software and record independently for each of them. Since optimized and specialized software is used, the requirements for this type of equipment are not as high as when organizing video surveillance on a PC. But the more channels in the device, the more powerful the processor and the greater the amount of RAM. In the case of an IP DVR, you don't have to worry about this, since the characteristics are always balanced.
number of hard drives.
This characteristic determines the maximum recording duration and the depth of the video archive. Models with 2, 4, 6, 8, 12, and 16 hot-swappable hard drives.
IP video recorders
IP video recorders. These devices are used to record, store and play video transmitted by IP cameras. The main criteria for choosing this device are the following technical characteristics:
video format.
The best formats today are H.264, H.265, MJPEG and MPEG4. They provide high-quality video recording with a high frame rate per second with a relatively small amount of traffic.
I/O ports.
Allows you to connect the IP DVR to a TV, monitor or other display device. There may be ports for external drives eSATA, USB2.0, USB3.0 and others.
Servers
IP video surveillance servers. These highly intelligent devices are capable of processing incoming information from connected surveillance cameras. Using equipment of this type, it is possible to minimize human intervention in the video surveillance process: by setting the appropriate settings, the specialist is able to program a whole sequence of actions for the connected network equipment when suspicious activity is detected in the frame. In addition to the characteristics indicated above for DVRs, experts also recommend paying attention to the following parameters:
Operating system.
Most often, manufacturers use operating systems such as Microsoft Windows and GNU / Linux in their developments. Despite the fact that the first of these operating systems is more understandable for most users, the second one is able to provide a higher level of reliability due to the complete elimination of the possibility of “infecting” the device with malicious software codes.
Compatibility with analog cameras.
Some video server models are capable of processing both digital and analog streams. This solution will minimize the total cost of ownership of a video surveillance system by using previously purchased devices.
