Research And Development Of Video Monitoring System Based On Network

It is universally accepted that 70% of information useful for people is obtained by human's vision. Vision information has many advantages such as direct and reliable. Along with the development of economy society, there is a sharp increase of the demand for the safety and spot record alarm system in the fields of bank, electric power, transportation, security, storage, construction and military infrastructure, etc. These requirements accelerate the improvement of video monitoring system. And the evolution of the computer which is more and more excellent in its operation speed, capacity and image processing also plays an important role in popularizing video monitory system.Traditional analog video monitoring system is on its way to digital, networked, and intelligent application, and is gradually replaced by digital system. Digital camera with USB interface gains abroad utilization due to its performance, low price. And because of the features of flexibility and conveniences, it can be integrated into system. Capture video by using digital camera with USB interface could greatly decrease the cost of video capture system, and enhance the compatibility and maintainability, and has already been used in PC recently in a large amount with a good effect. In the aspect of network video transferring, the transmission of video and audio through IP networks becomes a tendency. As for it, the association of the monitoring function and the technique of IP networks will be the direction of digital monitoring fields, and with the predominance of the two, it will have a promising future.According to the present status and based on the project, the thesis designed network video monitoring system run on Windows XP operating system through Visual C++. The system deployed client/server mode, and transmitted the picture from server end to client end connected with the server. The thesis, present status and progress tendency of video monitoring were first introduced. And a discussing over the technique of digital video compressing, network transmission, DirectShow, COM, and multithread was given. Afterwards, the thesis put a focus on the design and analysis of the system, and primary module was realized. What's more, the optimization of the system including the detection of image movement and alarm was also carried out. At last the thesis presented a summarization and expectation.The system was on the platform of Windows XP. Owing to its superiority such as multimedia processing, network function supported by multi-protocol, plug and play of hardware equipment, many application programs are developed based on it.And Visual C++ was adopted as the tool of programming software for the following reasons. First, VC is the circumstance of C++, and the C++ language is more abroad than other languages in its function and application. Second, VC is a kind of visible programming tool produced by Microware, and is not only a compiler but also consists of single modules such as debug and sorts of facilities designed for application program.The system made use of DirectShow which has two primary functions: media replay and media capture to implement network video technology. Therefore it is convenient for any application program which demands the operation of media replay.The most important part discussed in the thesis was the realization of video capture and display and also the Filter needed in the system. The system was made up of several modules: video capture module from server, MPEG4 compressing coding module, transmitting module, receiving module of client, MPEG4 decoding module, and display module. Video server included USB camera and PC. PC took charge of running server software and the registering of former end to common video server, and at the same time, it completed the capture, coding, display and storing of local video and packeting it to transmit. The network was LAN with Ethernet 100Mbps switch. Client part consisted of computers, client software. By running the software on computers, it provided identity authentication for the former end video server and received compressed video which would be decoded and displayed later from the monitoring system.The thesis also did some amelioration of it, which is primarily put on the aspect of movement detection and alarm. Several algorithm of detecting image movement were analyzed and the way of frame subtracting was selected according to the reality. As to the alarm, short message alarm was described in the thesis. TC35 short message module of SIMENS was expected to utilize for alarming, which is low in price and support the function of multiple sending.To sum up, in this thesis the key technology of video communication was researched, and a deep analysis was given to the difficulty of implementing the system. The network video Filter based on MPEG4 format worked by the thesis will be a reference and have the utility value for the later research. Due to limited time, this system is not perfect, and the author will improve it during afterward work.