The most common resolution is:

HD (720p) – 1280×720 (1 MP) – medium resolution, suitable for general assessment of the surveillance area.
SXGA (960p) – 1280×960 (1.3 MP) – increased number of pixels vertically for a specific, stretched-up scene.
Full HD (1080p) – 1920×1080 (2 MP) – human-identifiable resolution.
Quad HD (1440p) – 2560×1440 (4MP) – improved detail with medium bandwidth requirements.
5MP – 2560×1920 (5MP) – high detail, crisp picture.
4K UHD or Ultra HD (2160p) – 3840×2160 (8 MP) – excellent image quality, fine detail detection, the ability to use digital zoom.
With the development of digital technology, the tendency to increase the number of effective pixels is increasing, although high resolution is only relevant at sites where you need to clearly see the value and number of the bill, recognize the license plate at a great distance, constantly zooming the picture.

IP-camera lenses
Structurally, the lens is a complex system of lenses, enclosed in a frame and mutually compensating optical distortions. It collects and projects light energy onto a light-sensitive matrix to form an optical image.

The main parameter is the focal length (measured in millimeters), which determines the angle of view and the scale of the image. It is the distance from the axis of the lens set to the focal point (the intersection point of the originally parallel rays after passing through the lens). The smaller the focal length, the larger the field of view. A 2.8 mm lens provides video surveillance in a sector with a viewing angle of ~100º. The higher the focus of the camera (e.g. 8 mm), the smaller the angle of view, but the greater the required distance to the observed object for quality photography.

Video surveillance systems have different tasks, so IP cameras use short-focus, long-focus and ultra-long-focus lenses of different types: fixed focal length, variable focal length, motorized and fisheye.

Fixed focal length lenses
Focal lengths are set at the factory and remain constant throughout use.

Variable focal length lenses
These lenses have focal lengths set from short to long (2.7 ~ 13.5 for example) – they can be changed. IP camera with such optics is much easier to install, an order of magnitude more places for installation.

Motorized lens is equipped with an actuator (usually servo) – for remote control of focus and zoom. Often the motor-zoom includes an optical stabilization system, focusing and iris. IP-camera with zoom are in demand at high-security sites with a need to scale the image almost instantly (zoom rate not exceeding 5 seconds).

Fisheye
Fisheye lenses are very wide-angle (up to 180°), which is why the raw image is characterized by a distorted display of straight lines in the form of arched curves. Fisheye-equipped camera images are divided into separate channels by software (built-in IP camera or separately purchased software), correcting distortion at the same time. Fisheye camera replaces several conventional cameras.

IP Camera Form Factor
IP-cameras are available in dome, cylindrical, standard design (box), cube, spherical form factors.

Dome IP cameras are the most popular. Designed for horizontal (ceiling) mounting, but special brackets allow installation on a vertical plane.

Cylindrical IP-cameras are installed on a swivel bracket. Adjustment is used to set the direction of view. IP-camera bullet is often performed in dust-and-moisture-proof and vandal-proof housing, with a visor protecting from direct jets of water and sunlight, with a wide range of operating temperatures. Typically mounted on a vertical surface: wall, pole, fence.

Body cameras or cameras of standard design are mainly produced without a lens and mounting bracket, leaving the installer a wide choice of installation and equipment of the device, which increases the flexibility of configuration and expands the scope of the model. Built-in thermal housing adapts the camera to outdoor conditions.

IP-camera form factor Cube is designed for indoor use, equipped with a bracket for mounting on the ceiling, wall, table (desktop mounting is most popular).

Sphere – a form factor that determines the direction of IP-camera surveillance: the ball is simply rotated to the desired side – there is no dome, it is not necessary to remove it. A special screen is provided to protect the lens.

A separate group of IP cameras are rotary cameras. They support PTZ technology, use special software and drives to rotate and tilt the body for maximum level of control and coverage of a larger surveillance area. IP pan-tilt cameras with autotracking and motion detection independently follow the object of observation throughout the monitored area.

There are also highly specialized models that do not fit into any of the standard form factors, such as remote lenses (for retail).

Design of IP Cameras
IP cameras are produced for indoor, outdoor and transport applications.

Outdoor IP cameras meet specific requirements:

Compliance of the enclosure with the International Protection Marking (IP) for dust and moisture protection. The first number is protection against foreign objects (dust), the second – against the penetration of water. IP cameras for outdoor use must have an IP54 ~ IP68 rating.
Operating temperature range (provided that the enclosure meets the IP54 ~ IP68 protection standard). At minus 10 ° C – the camera can be installed in unheated rooms, at minus 20 ° C – outdoors in southern regions of Russia and the CIS, at minus 40 ° C – almost anywhere, and at minus 60 ° C – outdoors even in areas of the Far North (in such IP-cameras have protection against corrosion and icing).
Outdoor IP cameras

Transport IP cameras are specialized equipment, protected from vibration, equipped with special reliable connectors (usually threaded M12). Each transport IP camera is subject to mandatory conformity certification.

IP cameras for transport

Regardless of the purpose, for installation in places that are not in sight of security guards, IP-cameras are produced, protected from mechanical influences of varying degrees – the body corresponds to the international classification code IK08 ~ IK10.

The post Camera Features appeared first on Getbutterfleye.

With built-in motion detection or virtual line cross detection, an IP camera starts recording only when the sensor signal (if configured) – reducing the load on the network, creating significant savings in archive space, bandwidth resources, equipment depreciation and operator time for viewing.

Compression
Unlike traditional CCTV cameras, IP cameras compress the stream – they process it on-board with video codecs. Traditional ones transmit an uncompressed signal, straining the server and requiring high capacity. The uncompressed analog signal needs to be converted – with inevitable losses in quality. IP cameras are not limited to analog video standards.

The most common video codecs are JPEG for static images, MJPEG for dynamic (in motion) images and H.264 and H.265 for proprietary (paid) images. The strongest compression is demonstrated by H.265, but it is most effective at high resolution, and it is practically unnecessary for 2 megapixels. Developers continue to improve codecs and intelligent compression technologies.

Edge Storage internal video archive
Edge Storage – local storage of information, recording video on the internal memory card, creating a double archive for insurance in case of connection failure. If necessary, IP-camera works independently – without connecting to a video recorder or PC. The IP-camera has a slot for microSD/SDHC/SDXC memory card or USB port for USB flash drive connection.

Multistreaming
IP cameras broadcast not a single stream, but several streams – at least two: the main stream in full resolution for recording and a sub-stream of a smaller resolution for the monitor. Most IP cameras support three streams – to record, to monitor, to mobile device, and some models support up to ten streams. Separate streams are allocated to different detectors to reduce the load on the server and network.

Corridor Mode
Many IP cameras support corridor mode – a vertical display of video, 9:16 instead of 16:9. In this mode, it is convenient to view footage of corridors, tunnels, and so on. The support of the mode is specified in the specification of the IP camera. If the corridor mode is not specified, you cannot get the function programmatically – the required resolution is set on the hardware level.

Audio
In general, IP-cameras are equipped with one or more audio inputs and audio outputs, transmit audio files to the recorder and receive the audio signal. Some models already have a built-in microphone, but if necessary, each IP camera with an audio input can be connected to a professional omnidirectional, bi-directional or unidirectional microphone (depending on the application).

There are analytic functions that work specifically with sound, identifying over or under the sound threshold (the threshold is set by the user in the settings), scream, glass breaking, gunshot, explosion and other harsh sounds and create alarm events to be sent to the system.

CMOS sensor IP camera
Matrix – the main element of the camera, converts light into electricity, is a specialized integrated circuit, consisting of light-sensitive photodiodes and operates on a particular technology. The importance of the matrix is great: even with a powerful processor, if the sensor produces a bad image, it is impossible to improve it.

Advantages of CMOS matrices:

Lower cost than CCDs, especially at larger sizes.

Progressive scan technology.

Unity of technology with other digital devices; possibility to combine digital, analog and processing parts on one chip.
High quality color rendering.
Low power consumption, which is especially important in IP-cameras, which start shooting by the signal of the detector, in non-volatile devices of video surveillance and ACS.
High speed frame reading, which increases the speed of recording, the possibility of high-quality manual focus.
Increased sensitivity in low light conditions due to the amplified stages (placement of circuits in any place in the signal path), the possibility of changing the gain for each color, improved white balance.
High performance.
Low bandwidth requirements, ability to reduce bit rate.
Progressive scan – a method of displaying, transmitting, and storing moving images with all lines of a frame in sequence. This requires twice the bandwidth of interlaced scanning, but the advantages of the method far outweigh the disadvantage.

Benefits of Progressive Scan:

No “combing” or flickering on the moving object, no need to apply picture anti-aliasing, introducing distortion.
Quality enlargement of the image to a higher resolution.
Safeguarding each frame in one piece (no separation into two fields).
Matrix size is also important. The size is given in inches, as a fraction. The smaller is the denominator, the bigger is the sensor size, the better (but more expensive and heavier) is the IP camera base: optimal color rendering, higher is the signal/noise ratio, higher is the image quality, larger is the viewing angle with a lens with the same focal length.

The most popular formats are:

1/2″ – sufficient light sensitivity in most cases.
1/3″ – good performance in low light and high frame rate.
1/4″ – minimum size and low sensitivity.
Multi-sensor cameras are built with multiple sensors – to get a panorama or several scenes from one IP camera.

The post The main advantages of IP cameras appeared first on Getbutterfleye.

How an IP camera works
The lens focuses the image on the sensor. The sensor converts the color into an electrical signal. The signal goes to the processor for color, brightness, and other processing. The video stream goes to the compressor. The compressor compresses the stream – the data is now ready to be sent to the network via an Ethernet controller.

Each IP camera has its own IP address transmitted with the connection and used to synchronize the camera with the recorder: With a command or a special program, the recorder uses the IP address of the camera and connects to it. Without an IP address, it is not possible to set up the equipment to work together or to access the IP camera from a mobile device.

Thanks to digital stuffing IP-camera functionality tends to infinity at the expense of variety of software, and data can be accessed from any remote place of the planet where there is internet.

What IP cameras are connected to
IP camera transmits the video stream to a recorder (server), PC (with appropriate software), in the cloud (SaaS solution, software as a service).

Several IP-cameras are connected to the recorder via a router, switch or each to a separate port (if available). A router or switch that supports the network protocol of dynamic node configuration automatically distributes addresses and other network settings.

IP camera – low power equipment. Powered by an adapter, PoE switch or DVR if it supports PoE. PoE – Power over Ethernet, supplying power via Ethernet network, over twisted pair simultaneously with data broadcasting.

Connecting IP-cameras to PC depends on the number: if one camera, connect to LAN-interface of network card, if a few, connect to LAN switch, and already to it – IP-cameras, then make a network connection with assigning each a new network address.

Data transmission mechanisms, network and protocols
IP cameras work with the TCP/IP protocol stack. TCP/IP is a networking model with four layers of data flow: application, transport, network, network access.

Distribution of protocols by layer:

Application – HTTP, RTSP, FTP, DNS, etc.
Transport – TCP, UDP, SCTP, DCCP, etc. (RIP, routing protocols such as OSPF, working on top of IP – part of the network layer).
Network – IP (auxiliary protocols, such as ICMP and IGMP, working on top of the network protocol, but belonging to the network layer, and ARP – an independent auxiliary protocol, working on top of the data link layer).
Network Access Layer – Ethernet, IEEE 802.11 WLAN, SLIP, Token Ring, ATM and MPLS, physical media and information coding principles, T1, E1.
Transport protocols
TCP – guaranteed protocol (in the first test the package went 150,000 km without losing a single bit of information), it uses commands to pre-establish a connection, then starts transmitting data; it keeps track of the data and their sequence, adjusts the translation speed so that the data are not transmitted more heavily than they can be received. Corrects errors – sends a double if a packet is lost, and corrects an error if two identical packets arrived at the same address.

RTP is a protocol for transmitting traffic in real time. It includes data synchronization and packet sequence correction.

UDP – is an alternative to TCP, but does not establish a preliminary connection, and immediately begins broadcasting. It does not watch for data reception and does not duplicate in case of lost packet retrieval. Less reliable, but faster.

In terms of speed and transmission of real-time traffic, it is preferable to RTP or UDP, but in problematic networks, TCP is indispensable, because it corrects errors and corrects failures.

Interoperability protocols
Devices from one vendor are compatible by default. IP cameras support application protocols for compatibility with devices from other manufacturers. Mainly RTSP and ONVIF.

RTSP is an application protocol for remote control of an IP camera, with a description of flow control commands. Provides solely control of IP cameras by a server. It has nothing to do with compression, packets, transport protocol definition. Data transmission as such is not part of RTSP – there is a standard real-time transport protocol for that. RTSP requests go separately from the stream – through a special port.

The Profile S specifications define:

Configuration of the network interface.
Discovery of devices using the WS-Discovery protocol.
Management of camera operation profiles.
Streaming configuration.
Event handling.
PTZ control.
Security (access, encryption).
IP camera with internal archive meets the requirements of the two specification profiles.

How the IP camera transmits its signal
There are three ways: wired, wireless and hybrid (two ways: wired and wireless).

Wired connection provides a stable and high-speed broadcast, but requires the installation of networks that are limited in length by the type of cable: 100 m for twisted pair, 500 m for coaxial, 100 km for fiber optic (not including repeaters or switches).

For wireless broadcasting, the IP camera is built in Wi-Fi module (most often) or 3G/4G module. Transmission range is limited and reduced due to physical obstacles in the direction of the router and electromagnetic interference.

IP cameras with hybrid data transmission use wired and wireless communication, providing increased reliability of the local network.

Ethernet: The IP camera’s transmission medium
The IP camera runs on an Ethernet network, a technology that connects devices into a local area network (LAN) for packetized data transmission. A video surveillance system based on IP cameras needs only the usual local office network that habitually connects computers.

Ethernet is described by the standards of the IEEE 802.3 group. The standards define frame formats and medium access control protocols at the data link layer of the model of interaction between devices with each other.

A brief list of network modifications to the standards (maximum segment length is specified)

1. Over twisted pair:

Ethernet, 10 Mbps: 10BASE-T – Cat. 3 and higher, 10BASE-T – two twisted pair Cat. 3 or Cat. 5 (100 м).
Fast Ethernet, 100 Mbps: 100BASE-T – Cat. 3 and Cat. 5 (100 м).
Gigabit Ethernet, 1000 Mbps: 1000BASE-T – Cat. 5e (100 m).
Intermediate Ethernet standards, 2.5 Gbit/s and 5 Gbit/s, respectively: 2.5 GBASE-T and 5GBASE-T – Cat 5e and Cat 6 (100 m).
10 Gigabit Ethernet, 10 Gbit/s: 10GBASE-T – cat. 6 (55 m) and 6a (100 m).
IP camera network interface – RJ45
IP camera network connector

2. Via coaxial cable at 10 Mbps: 10BASE5 – RG-58 (up to 185 m), 10BASE2 – RG-8 (500 m).
3. Optical cable (single-mode – fiber with the core diameter 7 ~ 10 times the wavelength of the light passing through it, multi-mode – fiber with a larger core diameter, which conducts light rays due to the total internal reflection):

Ethernet, 10 Mbit/s: FOIRL – up to 1 km, 10BASE-FL – up to 2 km.
Fast Ethernet, 100 Mbit/s: 100BASE-FX – multimode fiber, 400 m/2 km (half duplex/duplex*), 100BASE-SX – multimode fiber, 2 km/10 km (half duplex/duplex), 100BASE-FX WDM – singlemode fiber (primary use – transceivers).
Gigabit Ethernet, 1000 Mbit/s: 1000BASE-SX – multimode fiber (500 m), 1000BASE-LX – multimode fiber (550 m), single-mode fiber (5 km), 1000BASE-LH – single-mode fiber (100 km).
10 Gigabit Ethernet, 10 Gbit/s: several standards, from 26 m to 40 km.
Faster Ethernet is not yet used in video surveillance systems.

*Duplex mode of data exchange – sending and receiving simultaneously on two communication channels, half-duplex – one channel at a time.

To broadcast over coaxial and fiber optic cable you need a signal extender for coaxial cable and SFP-module for fiber optic. Sometimes the fiber port is built into the IP camera, but in most cases the network is laid at the switch level with SFP ports.

Features of IP-Surveillance Cameras
The main difference and the first advantage of an IP-Surveillance Network Camera is the digital video signal from the light sensor to the server.

The post IP camera: what it is, how it works appeared first on Getbutterfleye.