Fast, Robust and Accurate Digital Image Correlation Calculation Without Redundant Computations
Fast, Robust and Accurate Digital Image Correlation Calculation Without Redundant Computations
复制标题
快速、稳健且准确的数字图像相关计算，无需冗余计算
DOI：
10.1007/s11340-013-9717-6
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发表时间：
2013-09-01
影响因子：
2.4
通讯作者：
Tong, W.
中科院分区：
文献类型：
--
作者：
Pan, B.;Li, K.;Tong, W.
近年来，考虑到使用更高分辨率的数码相机的持续趋势以及处理动态测试中记录的大序列图像的普遍要求，使用数字图像相关（DIC）的高效且高精度的变形分析变得越来越重要。为了在不牺牲亚像素配准精度的前提下，消除传统的基于前向加性匹配策略的DIC方法和经典的Newton-Raphson（FA-NR）算法中的冗余计算，提出了一种基于逆合成匹配策略和高斯-牛顿（IC-GN）算法的DIC方法，以实现快速、鲁棒和精确的全场位移测量。为此，首先，一个有效的IC-GN算法，而不需要重新评估和逆Hessian矩阵在每次迭代中，被引入到优化的鲁棒零均值归一化平方差和（ZNSSD）标准，以确定所需的变形参数的每个询问子集。然后，一个改进的可靠性引导的位移跟踪策略，以实现进一步的速度优势，自动提供准确和完整的初始猜测的变形的IC-GN算法上实现的每个计算点。最后，一个易于实现的插值系数查找表的方法，以避免重复计算的双三次插值在亚像素的位置。通过上述改进，完全消除了传统DIC方法中涉及的各种过程（即变形的初始猜测、亚像素位移配准和亚像素强度插值）中的冗余计算。用数值实验和真实的实验图像对所提出的DIC方法的配准精度和计算效率进行了仔细的测试。实验结果表明，本文提出的基于IC-GN算法的DIC方法与现有的基于经典FA-NR算法的DIC方法的结果相似，但前者的速度要快3 ~ 5倍。该算法有望成为DIC中一种新的标准全场位移跟踪算法。
High-efficiency and high-accuracy deformation analysis using digital image correlation (DIC) has become increasingly important in recent years, considering the ongoing trend of using higher resolution digital cameras and common requirement of processing a large sequence of images recorded in a dynamic testing. In this work, to eliminate the redundant computations involved in conventional DIC method using forward additive matching strategy and classic Newton–Raphson (FA-NR) algorithm without sacrificing its sub-pixel registration accuracy, we proposed an equivalent but more efficient DIC method by combining inverse compositional matching strategy and Gauss-Newton (IC-GN) algorithm for fast, robust and accurate full-field displacement measurement. To this purpose, first, an efficient IC-GN algorithm, without the need of re-evaluating and inverting Hessian matrix in each iteration, is introduced to optimize the robust zero-mean normalized sum of squared difference (ZNSSD) criterion to determine the desired deformation parameters of each interrogated subset. Then, an improved reliability-guided displacement tracking strategy is employed to achieve further speed advantage by automatically providing accurate and complete initial guess of deformation for the IC-GN algorithm implemented on each calculation point. Finally, an easy-to-implement interpolation coefficient look-up table approach is employed to avoid the repeated calculation of bicubic interpolation at sub-pixel locations. With the above improvements, redundant calculations involved in various procedures (i.e. initial guess of deformation, sub-pixel displacement registration and sub-pixel intensity interpolation) of conventional DIC method are entirely eliminated. The registration accuracy and computational efficiency of the proposed DIC method are carefully tested using numerical experiments and real experimental images. Experimental results verify that the proposed DIC method using IC-GN algorithm and the existing DIC method using classic FA-NR algorithm generate similar results, but the former is about three to five times faster. The proposed reliability-guided IC-GN algorithm is expected to be a new standard full-field displacement tracking algorithm in DIC.