Introduction
With communication, computer, multimedia technology development, and
security, financial, education, etc, the customer demand growth increasingly
remote video monitor system of large-scale construction is rapidly across the
country. Video monitoring in the simulation model combining monitor, monitor and
control the development of digital after becoming, networking, platform,
large-scale, integrated the direction of development.
The traditional video monitoring technology has failed to meet the new
business needs and new business model. Video monitoring of development, and the
need of various technical innovation, and comprehensive. Video monitoring system
of the future will be various advanced technology. Below is a brief discussion
of current video monitoring needs to use all sorts of technologies.
Streaming media technology
Real-time video surveillance video monitor and replays are two important
basic business, its essence is the source of the multimedia video will transfer
data to video receiver. Real-time video surveillance video requirement of
real-time transmission of real-time performance, strong, Replays is similar to
the business, have certain VOD real-time (but not very clear pictures, smooth,
and can perform a variety of broadcast control operation.
We can be in front of the camera is regarded as the source of A/V
real-time video files, and will be considered A/V file storage, then solve the
problems of the present is A good way to use streaming media technology.
We know, streaming media stream and StreamingMedia () is in order to solve
the problem of information transmission of real-time and development. Streaming
media through the network transmission mainly refers to the audio and video
(such as the technology transfer, etc.) for the specific meaning through the
network information transmission to the video will be broadcast, without end
users download files etc all can play, but after the audio and video information
will put in server, after compression played during the user terminals as part
of the content will start in its memory, the data flow by user terminals in the
background to continue receiving and play, play or suspended until the user
operation. So, the user will be broadcast media of waiting time, and no
significant reduction in large cache. Streaming media technology to use
streaming media when the yankees continuously.
Streaming is mainly to distinguish from the download transmission.
Traditional way of losing download turn two basic conditions, one is based on
documents, file to operate all after download can use (play). For real-time
video surveillance, the concept of file does not exist, and therefore cannot use
"download" means. For video, the video data can be in business documents, but,
if the video data if must download completely to play, will bring large time
delay, the user can endure. Therefore, an ideal way is using streaming.
Realizing streaming in order ProgressiveStreaming) and streaming
(real-time streaming (RealtimeStreaming) two methods. Video monitoring business
mainly using real-time streaming.
Network cameras can be regarded as A provides real-time A/V source of the
server, when the user requests for real-time surveillance camera, network using
real-time streaming terminals to user mode transmit supervisory picture.
Considering the multiple users access network cameras will also bring bottleneck
problems, such as flow can be used to transfer video server, make video server
to provide powerful load capacity.
Above is the rational brief explanation. The scheme can satisfy the video
monitoring system, small in large video monitoring system, monitor equipment and
user terminals in front of the huge number, in addition to increasing is
considering multicast, broadcast, the more need a perfect media distribution,
scheduling mechanism to ensure the effective transmission media. In this aspect,
at present there is no ready-made mature solution, China communications
standardization organization (CCSA) are studied, in order to have the video
monitoring system for the future of the media transmission mechanism provides
standard.
Transformed technology
Mentioned, we first thought transformed must be instant communication
(IM). Video monitor and transformed technology and combining seems to be a
relatively new formulation. In a traditional way to think, it seems not too big.
Actually otherwise, can be very good for transformed in video monitoring
service.
"PresenceInformation transformed, too," Chinese generally translated as
"present" to convey the user and a group of users through communication
equipment. The most commonly used immediately transformed in the communication
tools, for example, in many IM software: online, busy, left, etc. That is
offline These he called "state", they transformed the current state of the sort.
At the same time, the state with the user reflects with other users, such as the
ability to communicate in "weaning" if users, other users cannot use instant
messaging and communication.
One of the most simple transformed as follows: a user process (called the
Watcher) subscriptions (by) he is interested in another user (Presentity),
Presentity accept subscriptions transformed. Presentity after the state change
after he would PUBLISH) (their new condition, the new state will NOTIFY) give
notice (Watcher. Below are RFC2778 is transformed the model.
From the perspective of system, video surveillance equipment and each of
the monitoring system of the front IM users have many similarities, for example,
the system should always understand each monitoring front-end equipment (1) are
already login system, (2) have the ability to set (such as what if what
encoding, support, support encryption PTZ supports remote control whether), (3)
is being user access and what users access, etc.
We find these "status" maintenance is transformed the technology of good.
Visible, if can be transformed to the technical achievement, video surveillance
system will bring great convenience.
Intelligent video technology
Intelligent video surveillance network video monitoring is one of the most
field application modes.
Intelligent video (IV), IntelligentVideo from computer vision (CV,
ComputerVision) technology. The computer vision is artificial intelligence (AI),
one of the study ArtificialIntelligent branch, it can be described in the image
and the mapping relation between image, which can be calculated by the digital
image processing and analysis to understand the content of video images.
Video monitoring mentioned in the video intelligent technology mainly
refers to: "automatic analysis and extraction of video source key information."
If the camera as people's eyes, and intelligent video system or equipment, can
be regarded as the human brain.
Build video monitoring system, the purpose is to a vision to go up is
outspread, the picture is a land through network and equipment "close" to the
eyes, and therefore have the remote monitoring, 2 it is for intellectual
extensions - let the system automatically for us to analyze and solve problems,
then the intelligent monitoring. Of course, the latter is on a higher level of
video surveillance, but also the inevitable requirement of development in the
future.
Video monitoring system, lack of traditional intelligence, rely heavily on
man's judgment. However, the human has its hard to overcome weaknesses, such as:
(1) limited, one of the human reaction and processing speed limited, causing us
within the time limit specified in the site to monitor. This also means that
each by decentralizing not zhongsheng is monitoring. Not a man (2) can fully
trustworthy observers, whether in watching the video or in real time watching
replays, because of their physical weakness, we often cannot detect security
threats, leading to the omission of the phenomenon.
From the above analysis, when the video monitoring, large-scale actually
has not dispensable intelligent monitoring system, but the adornment of a kind
of ability. Otherwise, the huge investment will follow due to lack of human
resources and human weaknesses, and may become a waste.
Intelligent video technology can be applied in many places. Such as:
(1) advanced video motion detecting: in the complex environment (for
example, fog rain, wind, etc) accurately detection and identification of a
single object or multiple objects, including the movement direction of movement,
the motion characteristics, etc.
(2) object tracking: detect moving objects, according to the movement of
objects, automatic control commands, PTZ send automatic tracking the camera to
the object, the object scope, automatic monitoring camera after notification
object in the region to tracking cameras.
(3) facial recognition: automatic identification characters of facial
features, and the characters and database files by comparison to verify the
identity of the character recognition or. This application and can be divided
into "guider" and "the two kinds of cooperative". "Guider" need to be monitored
in the camera for a period of time, usually with entrance guard system. "The
cooperative" can be identified in the crowd of specific individuals, such
application in airports, railway stations, sports venues such application
security role in the scene.
(4) : identification of vehicle identification of vehicle license plate
number shapes, colors, features, such as monitoring and feedback. Such
applications can be used in stolen vehicles and scene.
(5) illegal detention, when an object (e.g., box package, vehicles,
characters, etc.) in the sensitive area of time is too long, or more than the
length of predefined is alarming. A typical scenario including airports, railway
stations, bus station, etc.
(6) traffic control: used in highway traffic conditions, such as
monitoring statistics through the car number, average speed, whether there are
at fault, illegal vehicles, etc.
Wireless transmission technology
If the central control center monitoring and farther apart and position,
using traditional dispersed network wiring way not only cost is very high, but
once encounter obstacles, rivers and mountains is stranded cable networks. At
this time, the wireless network advantage can manifest. Using wireless
technology, and can be more Bridges with central control center spot is
connected, and build quickly, can in the shortest possible time quickly set up a
wireless network link.
In the wireless surveillance system, wireless Internet connections are
primarily as monitoring and control center data transmission link. Through
wireless networks can be multiple remote monitoring device for transmission,
video link, At the same time, because the quality of video monitoring system,
how to higher requirements on wireless network transmission stability of high
quality video surveillance system of wireless digital information is needed to
solve in one of the key technology, In addition, from engineering point of view,
the bridge equipment installed in the outdoor, how often to these equipment
long-distance power supply and equipment management is an issue.
Infrared thermal imaging technology
Human can feel the wavelength of visible light is 0.38 ~ 0.78 microns.
Infrared wavelength than 0.78 microns belongs to the electromagnetic waves. In
nature, all objects of different wavelengths of infrared radiation will,
therefore, can use special detecting equipment were detected the target and
background monitoring of infrared wavelengths, which can get different infrared
image, the infrared image called thermal images.
Using the infrared thermal imaging technology and detection of target
objects, and infrared radiation by photoelectric conversion, signal processing,
the temperature distribution of the object will convert video images of the
image is called infrared camera equipment.
In video monitoring infrared earners application examples:
1 night and harsh climate condition monitoring the target
At night, the equipment has been working to visible light can't work
normally, if using artificial lighting, easy to expose goals. If you use LLL
night-vision equipment, it is also working in the visible bands, still need to
external light. And infrared thermal earners are passive infrared radiation of
the target to accept oneself, can work day and night, and also not expose
yourself. Also in the rain and fog of bad weather conditions, due to the
wavelength of visible light is short, the ability to overcome obstacles, and
observation results, but the infrared wavelengths longer, especially in the hot
14um 8 ~ sounds, through the fog rain, strong ability in the night, so bad
weather conditions, and using infrared thermal imaging monitoring device can
still normal to monitor all targets.
2 fire monitoring
Because of the infrared thermal earners are reflected object surface
temperature and imaging equipment, so besides night scene monitoring can be
used, but also can serve as an effective fire alarm equipment. Many fires are
often not obvious by the YinHuo trigger. With the existing ordinary method, it
is very difficult to find the hidden fire symptom. And application of infrared
thermal earners can rapidly and efficiently, and can find these YinHuo
accurately determine the location of fire, smoke, and that, through the
ignition, prevention, early know earlier.
3 and the concealment of target identification of disguise
In visible light camouflage is observed, criminals usually hidden when
crime in the grass and woods, due to the wild environment of bad and visual
illusion, easy to produce false. Infrared thermal earners are passive acceptance
goals of radiation, human and their vehicles of temperature and infrared
radiation generally far outweigh the vegetation of the infrared radiation,
temperature and so easily disguise, also not easy to produce false.
Video monitoring is actually a very large and complex communication
system, which involves all aspects of various techniques. The author believes
that the above list is relatively important some technology. All of these
technologies are in continuous development, the development of video monitoring
technology directly push the development.
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