【摘要】 通过对数字激光散斑图像特性的分析及其位移测量法的研究,给出了一种利用激光散斑图像进行位移测量的多层平截算法。该算法把数字激光散斑图像的灰度看作三维空间的高度,用不同高度的水平面平截散斑图得到截值点,分析物体发生位移前后的散斑图像上截值点,由截值点相互位置的概率分布计算出物体的实际位移。改进后的多层平截算法可较大的节省测量所需的散斑图像面积,且能测量亚pixel级的位移。实验表明,该多层平截算法是一种实用、速度快及精度高的位移和变形测量方法。更多还原

【Abstract】 An improved displacement measurement method of digital laser speckle images using multi-level crossing technique is presented based on the analysis of digital laser speckle images’ characteristics and the displacement detection techniques. The gray levels of speckle images are cousidered as the height level if plotted in 3-D,and several horizontal levels are used to cut across the gray level of speckle images. The crossing points are analyzed,and the displacement can be extracted by the statistical histogram of these crossing points’ relative positions. If this multi-level crossing method is used, the sampling number of speckle pixels will be greatly reduced, the sub pixel displacement can be extracted, and the computing time will also be reduced. The experimental results show that this method is a feasible, fast and precise method for displacement and strain measurements.更多还原