Video monitoring system status and development (1)

Video surveillance system is an integral part of the security system, it is a preventive capacity strong comprehensive system.

Video surveillance with its intuitive, easy, and information content rich and widely used in many occasions. In recent years, with the computer, network, and image processing, transport, technology, video monitoring system technology is also well advanced.

A video surveillance system, system status

Currently, video surveillance system is in the development of CNC simulation system has been very mature, stable performance, in the actual work has been widely used, the rapid rise of digital system but is not yet fully mature digital and analog hybrid application and will gradually transition to digital system.

In both domestic and international markets, mainly to launch digital control of analog video surveillance and digital video surveillance both types of products.

The former technology development has been very mature, stable performance, in a real project application has been widely used, especially in large and medium-sized video surveillance project is particularly widespread in the application; the latter is a newly rising to computer technology and image and video compression new video surveillance system that solves the simulation system part, but you still need further improvement and development.

1. digital signal control of analog video monitoring system

Digital signal-controlled analog video monitoring system consists of microprocessor-based control of video switch plus PC multimedia management and PC-based host to matrix switching control and multimedia management system of two types.

1-1, switch the microprocessor-based control of video and PC multimedia management types

80 's is a microprocessor, video monitoring system using microprocessor firmware development Matrix Switchers originally distributed full hardware video surveillance systems, such as micro-centralized video switch, on the front side of the control features such as a machine together with the collection, processing, is a breakthrough technology.

-Microprocessor matrix hosts available through PC graphics management software implementation:

① on single workstations of video surveillance, access control, intercom, alarm, and more comprehensive control (Note: you can only provide a simple, you can improve system control function in the user interface, but cannot replace matrix hosts security configuration and programming skills);

② any workstation over the network, and control other workstations attached matrix, alarm device, complete video switching, head, camera control and alarm linkage, and other functions;

③ software implementation on many matrix hosts and alerting interface software modules for control.

1-2, PC-based host to matrix switch, control and management of multimedia systems

PC-based video monitoring system using software design, realization of the camera to monitor video matrix switches, tilt and lens control, through the serial port connection alarm device alarm information, and through programming to automate video switching, PTZ control, alarm, alarm, video, and other control functions.

The system can take full advantage of the PC's resources for video surveillance system with computer technology development and continuous improvement, while its open structure characteristics but also to other kinds of systems such as fire alarm systems, access control system, building automatic control system for interactive integration.

1-3, numerical simulation of the pros and cons of video monitoring system

With the microprocessor, a PC features, performance enhancements and improved application of multimedia technology, system functionality, performance, reliability, structure, style, and so on, great changes have taken place, the video monitoring system form more convenient and flexible, and other technical systems interface tends to norms, human-computer interaction interface more friendly.

But as the video monitoring system form of information flow has not changed, still analog video signals, and systems network architecture is primarily a single function, one-way, sets general information collection network, media-specific characteristics, the system only pipe has developed to a very high level, without too much potential, its limitations still exist, to meet the higher demands, the only way to digital is.

Analog control system of the main disadvantages are:

① usually suited to small-scale regional monitoring

Analog video signal transmission tool mainly coaxial cable, coaxial cable transmission distance of analog video signal is not greater than 1KM, twisted-pair short distance, which meant analog monitors only suitable for a single building, small settlements and other small places.

② system expandability difference

For already-built system, if you want to add a new control point, often led by a hair and body, the new device is also very difficult to add to the existing system;

③ could not form a valid alarm linkage

In analog surveillance system, as part of independent operation, mutual control protocol difficult interoperability, linkage can only to a limited extent.

2, digital video surveillance system

In the late 1990s, with multimedia, video compression technology, network communication technologies development, digital video surveillance system for the rapid rise, today's market, there are two types of digital video surveillance system, a digital video equipment is at the core of video surveillance systems, and the other is to embedded video Web server as the core of the video surveillance system.

2-1, digital surveillance video systems

Digital surveillance video systems are generally divided into two categories: one category is based on a combination of computer-PC multimedia works; embedded digital surveillance video systems.

① computer multimedia digital surveillance video systems

Digital video compression technology matures, the popularization of computers, PC-based control of multimedia.

This new video surveillance system for the rapid rise, partly replacesTo video matrix image splitter, video recorder, complemented by other transmitter analog video monitoring mode, the superiority of the main problems:

A, PC multimedia monitor host comprehensive video matrix, image segmentation, video recorder etc many features that make the system structure is greatly simplified.

B, as a result of computer network technology, digital multimedia remote network monitoring with no distance limitation;

C, due to the use of high-capacity disk array disk or compact disc storage, you can save a lot of tape media, at the same time contribute to realization of multimedia information query system.

But as the PC-based video surveillance video systems development, in a real project, also revealed some shortcomings, mainly the instability of the system work.

PC-based video surveillance video system structure is:

Compatibility/industrial control PC + video capture card + ordinary/more reliable [1] [2]