Research And Implementation Of Automatic Target Tracking Algorithm Based On PTZ System

Automatic target tracking algorithm based on PTZ system is a very important research area in intelligent video surveillance. It changes traditional PTZ system to track target that needs people operate the keyboard to control the platform rotation and lens zoom, and builds the PTZ auto-tracking model lens auto-zooming model to ensure the target can always display on the video screen center at the same size.Select the tracking target in the supervisory area. According to the target motion state, use the PTZ automatic target tracking algorithm to control the platform rotation to accomplish the target automatic tracking, meanwhile according to the target size in the screen, adjust the zoom and focus to make sure the target can display on the video screen center clearly at the same size. In this paper, the main work has:(1) Build the target motion trail, propose the Kalman filter combined with Camshift algorithm to lock the target in each frame image, and record the target position coordinates. Connect the target position to build the motion trail.(2) Build the platform automatic tracking model. According to the target motion trail, the platform track the target automatically. When the target horizontal moving distance and vertical moving distance are both greater than the platform minimum torque, use the paper proposed ladder rotation rules to control the platform to alternately rotate in horizontal and vertical directions. When the the target horizontal moving distance is less than the platform minimum torque, and the vertical moving distance is greater than the platform minimum torque, the platform only ratate in vertical direction. When the target horizontal moving distance and vertical moving distance are both less than the platform minimum torque, the platform donot ratate. Use the the platform automatic tracking model to always lock the target in the video screen center.(3) Build the lens automatic zoom model. Set a right area size, if the difference absolute value of the target size in the screen and the right area size is greater than the set area threshold, the lens need to zoom. Calculate the ratio of both, and multiply by the current lens zoom to get the change zoom. According to the multiples curve of lens to calculate the zoom time. Pull or push the lens to accomplish the lens zoom. Use the lens automatic zoom model to ensure the target can always display on the video screen center at the same size.(4) Compile the program of the PTZ automatic target tracking algorithm. Use the algorithm to track the moving target in groups of video to verify the effectiveness. The experimental results denote that this method can track the moving target accurately, adjust the PTZ timely and accomplish automatic target tracking.