Discontinuous and Pattern Matching algorithm to measure deformation having discontinuities

Abstract

Remote deformation monitoring with high accuracy is a challenging task. The technique of Digital Image Correction (DIC) is commonly used to measure remote deformation using images and provides high subpixel accuracy. However, DIC fails if deformation is non-continuous, which is a regularly occurring scenario in deformable solids due to the presence of discontinuities such as cracks and crevices. To overcome the limitation posed by DIC, a novel Discontinuous and Pattern Matching (DPM) algorithm is proposed in this study. Initially DPM algorithm demarcates the area where DIC fails by using the results of DIC. Later, DPM algorithm utilizes the features of pattern matching and embeds discontinuity in DIC to measure deformation in the demarcated areas where DIC failed. The performance of the proposed DPM algorithm is evaluated using two different experiments involving different types of discontinuities. The accuracy achieved in evaluation is higher than the normally required one-tenth of a pixel and the average absolute errors remained in the range of 0.02 to 0.07 pixels. The results are compared with another state-of-the-art DIC and pattern matching based technique and comparative analysis show that the proposed DPM algorithm improved the accuracy of deformation measurement in the range of 0.02 to 0.1 pixels depending on different scenarios.