Robust detection of moving target's height and trajectory using pan/tilt-embedded stereo camera system

摘要

In this paper, a new scheme for detection of the moving target's height and trajectory using the pan/tilt-embedded stereo camera system is suggested. That is, the moving target is extracted from the left image by using a threshold value of YCbCr color model and then, the location coordinates of the target can be obtained by carrying out the phase-type correlation between the segmented target image and the right image. At then, these values are used to control the pan/tilt system through the modified PID-based recursive controller. Moreover, with the geometric parameters between the target and stereo camera system, the distance from the center of the stereo camera system to the target and the direct distance from the camera to the target can be computed so that, the 3-dimensional location coordinates of the target can be finally obtained in the real world and as a result, the height value of the target can be extracted using the difference between z coordinate value of the target and the height of the pan/tilted-embedded stereo camera system on the desk. From some experiments using 780 frames of the input stereo image pairs, it is analyzed that error ratio of the position displacement of the target in the horizontal and vertical directions after tracking is kept to be very low value of 1.5%, 0.42%, respectively and error ratio between the measured and computed height value of the target is also kept to be very low value of 0.5% on average.