Video Surveillance Outdoors - From Simple in Past to Efficient in Future

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• Publié par: made-in-zelenograd-agency
• Nombre de lectures: 11
• Langue: English

Extrait

Video Surveillance Outdoors - From Simple in

Past to Efficient in Future

PR Newswire

MOSCOW, May 31, 2012

MOSCOW

,

May 31, 2012

/PRNewswire/ --

Every day we come across dozens or even hundreds of all kinds of video

cameras watching everything that is going on indoors and outside. Cameras

keep track of whatever happens around us. There is no place to hide, but the

cameras are there for our safety.

However, efficiency of outdoor video surveillance is far from perfect.

Comparison of conviction rates of crimes registered by indoor cameras and

those registered by outdoor cameras shows that outdoor cameras are much

less efficient, since the images are often so unclear that subjects cannot be

recognised. Because monitoring of large objects, such as streets, open areas,

parking lots or industrial protected areas, requires both coverage of the entire

territory and production of detailed images of individual areas.

Due to current rapid evolution of digital technologies, digital devices are

becoming smaller as their performance increases. Both consumer and

professional devices gain new advanced features. This certainly also affects

video surveillance systems.

So, can state-of-the-art developments leading to overhaul redesign of video

surveillance systems improve efficiency of outdoor monitoring? To answer this

question, let us consider the available configuration options for construction of

video surveillance systems intended for large territories and comprising

different types of cameras.

Outdoor CCTV cameras

In this scheme, video cameras are arranged to provide for the best view of

spots where people are likely to appear, or along the perimeter of the secured

site.

By now, the design of video surveillance systems for large open areas based

on standard analogue cameras proved to be impractical. These cameras have

very small fields of view, and large numbers of cameras and recorders are

required to provide proper detail. Such systems are more suited for smaller

objects, such as homes, offices or hotel lobbies.

Advantages:

low camera cost;

extendable without modernisation of the current video surveillance system.

Disadvantages:

low probability to reliable recognition of persons.

Digital megapixel cameras

Cameras of this class provide high-resolution images and allow to cover large

areas with minor quality loss. Large-size images provide enough detail for

recognition.

Such cameras would probably be the ideal choice for the discussed video

surveillance systems, if only they did not have one intrinsic deficiency - fixed

focus. The best definition is produced in the focal point only, while images of

anything located closer or further than that distance are processed by the

digital matrix (sensor) and contain distortions. The further the object is from the

focal point, the more distortion it has.

Advantages:

high-quality camera image.

Disadvantages:

large data stream generated;

high camera cost;

cannot be integrated into analogue surveillance systems.

Auto tracking PTZ cameras

These cameras are currently the optimum choice for surveillance of large

territories with low concentration of people. The camera can automatically

detect a moving object and follow it. This solution is ideal for extended objects

(such as streets or passages) with low traffic density.

However, this type of cameras have one substantial disadvantage. They are

able to analyse and "capture" moving objects only within their field of view.

Advantages:

automatic detection and tracking of moving objects;

can be integrated into analogue surveillance systems;

Disadvantages:

limited field of view in stand-by mode;

expensive.

Active tracking surveillance system

Active tracking surveillance systems are currently the most advanced trend

in development of video surveillance applications. This portable and at the

same time extremely powerful platform for 360-degree image analysis

provides efficient surveillance of the surrounding territory and intelligent

recognition of moving objects.

When a moving object is detected, the built-in PTZ camera points itself to the

respective sector, focuses and closes up on the object and tracks it. The

important advantage of the built-in control module is that several objects can

be "captured" and tracked at a time!

The main application areas of these systems include large objects with low

concentration of people (parking lots, etc.).

Advantages:

automatic detection and tracking of moving objects;

can be integrated into analogue surveillance systems;

360-degree surveillance in stand-by mode.

Disadvantages:

expensive.

Equivalent efficiency

Equivalent efficiency of each camera type may be estimated as follows:

20-megapixel digital camera =

45x

standard CCTV cameras;

active tracking surveillance system =

40x

20-megapixel digital cameras =

1800x

standard cameras.

Comparison of efficiency

Let us take the example of a system intended for surveillance of an outdoor

object. The key factor for our judgement will be reliable recognition of persons.

Auto

Active

Standard Digital

tracking tracking

CCTV

megapixel PTZ

surveillance

camera

camera

camera

system

Total system cost

high

med

low

low

Data stream generated

high

high

low

low

Number of recording devices

high

med

low

low

Ability to integration into

existing CCTV systems

high

low

high

high

Maintenance cost

high

low

low

low

General amount of detail in case

of small concentration of people

low

low

med

high

Amount of detail in case of large

concentration of people

high

high

low

low

Recognition reliability

low

high

high

high

The table shows that implementation of modern technologies in video

surveillance systems intended for large open areas definitely pays off due to

low overall cost and better detail.

Objects with large concentration of people will benefit from modernisation or

addition of megapixel cameras to the existing surveillance system.

For objects with low concentration of people and secured areas where

people are not expected to appear at all, the existing system should be updated

by adding either auto tracking PTZ cameras or an active tracking surveillance

system. The exact choice depends on particular configuration and typical

distribution of movements at the object.

SMP Group

is a leading Russian designer, developer and manufacturer of

Digital Video Recorders and other intelligent devices for CCTV systems. SMP

Group was formed in 1991, and since that time has been working in the sector

of state-of-the-art compact computer devices and software.

Contact

"Made in Zelenograd" Business Cooperation Agency

http://www.made-in-zelenograd.com