静爆试验测速图像中破片提取方法研究

Research on the Method of Extracting Fragments from Velocity Measurement Image of Static Explosion Testing

针对静爆试验中高速相机拍摄到的破片运动图像背景复杂、目标多、干扰多、破片小等问题,研究了小目标的增强和提取方法.提出了基于平方增强的三帧差分方法,得到破片运动的前景图像,增强了图像前景的信噪比;采用改进的最大类间方差法,得到更加精确的分割阈值,提高了目标分割精度;采用形态学处理方法,消除孤立噪点并恢复分割时削弱的目标边缘.实验结果表明,该方法能够很好地适应背景灰度的微弱变化,完成复杂背景下静爆图像中破片的提取,得到破片的运动轨迹,解决了采用高速摄影进行破片测速的关键问题,一定程度上有助于提高测速精度.

This paper presents a method for the enhancement and extraction of small targets in image sequence captured in static explosion test,whose background is complex with numerous targets,interferences and small segments.Three-frame difference method is adopted to process the original image sequence to obtain the foreground image.Since the foreground image is heavily contaminated by noise,so the gray square enhancement method is used to increase the contrast between the noise and the target.The modified Otsu method is employed to obtain the global optimum threshold,and the segmentation of the foreground image is accomplished.Finally,morphological processing is performed,and the noise of the isolated points is eliminated,and the weakening of the target in the process of differential and segmentation is resumed.Through a series of processing,the extraction of fragments in static explosion test image sequence is completed,and the trajectories of the fragments are obtained.