Design And Implementation Of Motion Detection In Video Monitoring System

With the large-scale application of video monitoring system, research and application of video monitoring system technology get more and more attention. As the basic requirement of sequence image processing in video monitoring system, motion detection has become one of the hot. By processing continuous sequence of video images coming from capture device, it detects and extracts moving objects in the images to get the target property using the target description, pattern matching. Further it determines the behavior of the target, trends and other information.In general, motion detection consists of the following steps: video decoding, image sequence smoothing, motion detection and eliminating the false positives. Gaussian Filter and Median Filter are the main methods for denoising of image sequence. Motion detection has the following method: Background Subtraction Algorithm, Frame Difference Algorithm and Optical Flow Algorithm. In practical video image sequence, the shadow of target, background disturbance and target occlusion will appear. Some appropriate algorithms are used to eliminate these effects.This paper focuses on the design and implementation of video monitoring system in the motion detection. Video monitoring system typically uses fixed capture device. Under this limitation this paper designs and implements motion detection algorithm. As the general steps in motion detection, this paper first introduces the Gaussian Filter and Median Filter to smooth image; then it compares Background Subtraction Algorithm, Frame Difference Algorithm and Optical Flow Algorithm; then Median Algorithm is designed for fixed cameras as the implementation for the system based on Background Subtraction Algorithm; then noise and target polymerization are analyzed as false positives, expansion method and area threshold method are give as the corresponding solution; and last implementation of the key algorithms and detailed test results are give based on OpenCV (Open Computer Vision).The experiments show that the system can effectively remove the noise, correctly identify the moving target, and reduce the false positives. This paper has some reference value for the design of motion detection in video monitoring system.