The Design And Realization For Intelligent Digital Video Monitoring System Based On Changes Of Linear Array Pixels

Digital video monitoring system is a kind of intelligent monitoring technology, including cameras for taking video, sound monitoring, probe reporting function and other devices. Because of huge information, direct vision, easy saving, complete function, quick control, it is widely used in the area of defending system and saves lots of manpower and material resources.Compared to traditional digital video monitoring system intelligent alarm is a new developing trend. In order to realize the function, the key technology is motion detection, that is to find changes between the two contigeous frames, so we can find the moving object invading into the space based still background.This thesis mainly studies video collecting, motion detection between two key frames and remote control. First get the video information from USB cameras and then analyse changes between key frames so to determine whether any object enters into the area or not. If so, then take snapshot immediately and send alarming signals to certain terminals.To the most important segment of motion detection, this article introduces a kind of algorithm for motion detection in still background by the camera in the front of the system. Compared to the traditional algorithm which involves subtraction of the whole pixels between two key frames, it makes simplification and improvement by dividing up the monitoring screen with several lines and calculating the changes of linear array pixels. The occupation of CPU in traditional algorithm is too huge when it works on video of high pixels, which results in problems as follows, system delay, video asynchronousism and influences the efficiency of real time monitoring. Without influencing accuracy of motion detection, it dramatically cuts down the time that calculating program takes and increases the efficiency of the system. And it can meet the demand of real time monitoring and motion detection of the digital video monitoring system. The entire video collecting system software platform based on Microsoft DirectShow SDK is developed by C++ language in Visual Studio integrate developing environment. The technological process of system is as follows:first get the video data from USB camera and pick key frames and compare the two contigeous frames simultaneously. If any change is real, then takes a snapshot and sends alarm signals to the user. The entire system is controlled on PC.After experiments, the algorithm raised by this thesis is proved to complete the function of motion detection successfully based on still background. What is more, improvements can be made to select the method of linear arrays so to accommodate concrete monitoring area. And enhance the practicability. To combine the current developing trend of digital video monitoring technology, this thesis makes forecasts in the aspects of internetization and remotation in intelligent monitoring technology and puts up with a few feasible methods of the realization in transmitting and receiving alarming signals.