Research And Design Of The Wireless Video Surveillance System

With the rapid development of the computer and communications technologies and the network technology,video surveillance used as a means of unmanned occasions has been more widely used. In the field of surveillance technology that integrated the video surveillance technology into network monitoring technology becomes the inevitable trend of the development. Internet the technology expands the capacity of the video surveillance system rapidly,it reduces the cost,completes Implementation of the long-range unmanned surveillance occasions. However,the previous cable video surveillance system will require a lot of equipment on underground lines,with the Poor mobility,the high cost and a long life cycle of construction. It becomes the constraints factors of the development of surveillance systems gradually. In the times of the computer communications technology increasingly moving into the wireless era,the technology of wireless network has become an essential component in the computer network. Its field of application is expanding rapidly and has shown a trend to replace the main status of wired network.Under the background of the data transfer information growing wirelessly,the wireless image transmission has become a new growth of the surveillance system. The wireless Image surveillance system not only shortened the time to install cabling,but also easy to expand the number of remote. Its mobility and convenience are better than networks,with the relatively lower costsThe video surveillance systems often use the PC as a core equipment of system. It has a greater advantage in handle of ability,but it almost impossible to match in the mobile and embedded devices. To build on wireless video surveillance system on embedded devices has become the main objective of its development.Against this background,through the structure on the wireless video surveillance system,the wireless video surveillance system is divided into video image acquisition system,wireless data communication systems,and embedded user platform. Video image acquisition system acquisition the video image into the memory,by running coding algorithm,make the video image data compression,and then the wireless data communications system make compressed data through a wireless network to transmission to users of embedded platforms. Finally the embedded processor platform users will receive the data into the original video decoder,and display the video image on the monitor of the platform.In the beginning of this paper,this paper introduced some technology of the wireless video applications,and the main processor what is used in video systems. Then this paper introduced the various types of processors against wireless video surveillance system what can be use. This paper described the needs of system,and the structure of the system,and proposing a solution of each part of the system. By comparison,the paper makes the decision.The Video image acquisition system is mainly responsible for the acquisition of image data and video data coding. The video image acquisition system is formed by the camera and embedded processors, and the camera will be responsible put the analog signal into a digital signal can be handled,and then transmitted to the processor for further processing. The processor is mainly responsible for the camera control, and image data transmission,compression coding procedures,such as the operation of the work.When implementing the Video Acquisition System,the compression algorithm are usually rather complex,so our requirements is relatively high to the processor performance. This paper selected processor of ADI-Blackfin for collection system. When prepared the software of acquisition System,the first is to be prepared by the driver of camera. First the video Capture procedure to complete the initial work of camera, then read the video images,store the video image into memory. Then call coding algorithm for data processing. When verification in this part of the system functions ,this paper mainly completed the acquisition of functional camera,It used visual DSP programming environment ADSP + +4.5 shown by the image collected by camera.When construction the system of wireless data transmission, which transmission technology are used affects the performance of the system directly. They include the General Packet Radio Service GPRS,and the wideband Code Division Multiple Access(W-CDMA),and the Bluetooth,and Wi-Fi(IEEE 802.11b),and so on. The various technical of transmission listed above,did not meet the requirements of the performance of this study system,therefore,this paper selected a transmission means which use the RF transmission technology as transmission system. The NRF905 is a equipment based on this technology.When communicated the wireless networks set up in the equipment, main tasks are:make the interface boards,and connect to a wireless transceiver module with control equipment,and prepared the driver of function device. It includes the function of device initialization,and the function of sending data,the function of data reception and so on. The initialization function include: RF configuration,and write the send data,and write into the sent address and so on. The functions of send and receive data include: control equipment,data packaging and so on.Embedded user platform is the most complex subsystems in all wireless video surveillance system. Its features include: video image display,video switching,data Grab and dealt with. Embedded platform responsible for reduce wireless data received by running the decoding algorithm restored to their original video signal,display on LCD in the final,and also be responsible for control of channel switching.The software of user platform mainly includes some of the major LCD driver and the video image display functions. Procedures initialize to the LCD on the first,then calls the decoding algorithm,reduced the data which received to video images. The partially used as a BF533 processor,and used the application of DMA technology in Data transmission aspects. External data through the processor interface PPI data will be sent to the data interface LCD,to realize the image display.This paper mainly discusses the framework of the subsystem architecture , and the hardware components in the wireless video surveillance system. This paper finds several of the proposed system for the realization and compares with various aspects of the comparison. Using existing equipment,this paper completed some functions,verified the feasibility,provided a certain amount of information in continue in-depth study on the wireless video surveillance system. AS the restrictions of personal capacity and the condition of existing equipment,this paper only achieves some functions of the system,it will still requires further in-depth study.