A fast digital image correlation method for deformation measurement
A fast digital image correlation method for deformation measurement
复制标题
一种快速数字图像相关变形测量方法
DOI：
10.1016/j.optlaseng.2011.02.023
复制
发表时间：
2011-07-01
影响因子：
4.6
通讯作者：
Li, Kai
中科院分区：
文献类型：
--
作者：
Pan, Bing;Li, Kai
近年来，利用数字图像相关技术（DIC）进行快速、高精度的变形分析变得越来越重要。在文献中，使用Newton-Rapshon（NR）算法的DIC方法被认为是精确亚像素位移跟踪的金标准，因为它对目标子集的相对变形和旋转不敏感，从而提供最高的亚像素配准精度和最广泛的适用性。然而，传统的基于NR算法的DIC方法的一个显著缺点是其极其巨大的计算开销。本文提出了一种快速DIC方法，有效地消除了传统的基于NR算法的DIC方法中的重复冗余计算。具体地说，采用可靠性引导的位移扫描策略，以避免耗时的整数像素位移搜索每个计算点，和预先计算的全局插值系数查找表，利用完全消除重复的插值计算在亚像素位置。通过这两种方法，所提出的快速DIC方法大大提高了传统的基于NR算法的DIC方法的计算效率。所提出的快速DIC方法的性能进行了仔细的测试真实的实验图像使用各种计算参数。结果表明，目前快速DIC的计算速度比传统方法快约120-200倍，而其测量精度没有任何损失（C）2011 Elsevier Ltd.保留所有权利。
Fast and high-accuracy deformation analysis using digital image correlation (DIC) has been increasingly important and highly demanded in recent years. In literature, the DIC method using the Newton-Rapshon (NR) algorithm has been considered as a gold standard for accurate sub-pixel displacement tracking, as it is insensitive to the relative deformation and rotation of the target subset and thus provides highest sub-pixel registration accuracy and widest applicability. A significant drawback of conventional NR-algorithm-based DIC method, however, is its extremely huge computational expense. In this paper, a fast DIC method is proposed deformation measurement by effectively eliminating the repeating redundant calculations involved in the conventional NR-algorithm-based DIC method. Specifically, a reliability-guided displacement scanning strategy is employed to avoid time-consuming integer-pixel displacement searching for each calculation point, and a pre-computed global interpolation coefficient look-up table is utilized to entirely eliminate repetitive interpolation calculation at sub-pixel locations. With these two approaches, the proposed fast DIC method substantially increases the calculation efficiency of the traditional NR-algorithm-based DIC method. The performance of proposed fast DIC method is carefully tested on real experimental images using various calculation parameters. Results reveal that the computational speed of the present fast DIC is about 120-200 times faster than that of the traditional method, without any loss of its measurement accuracy (C) 2011 Elsevier Ltd. All rights reserved.