Improved image-based, full-field structural displacement measurement using template matching and camera calibration methods

Although the use of artificial-markers improves the performance of the image-based procedures, there is a problem with the access to their installation place. Moreover, increasing the accuracy and efficiency of the available methods for structural-health-monitoring (SHM) is an important issue in recent years. Therefore, the purpose of this study is to enhance the image-based, full-field displacement measurement using new template-matching and camera-calibration methods. Furthermore, considering practical methods to increase the number of pixels in the images, the possibility of using free markers and improving the camera-calibration methods are investigated. The suitability of the proposed procedures was experimentally evaluated using single-degree-of-freedom and multi-degrees-of-freedom structural models and a railway bridge as a realistic application of the introduced methods. The proposed techniques are independent of employing artificial-markers or checkerboards with marker-less calibration abilities. Also, the effectiveness of the proposed schemes lies in the acceptable accuracy, computational efficiency, and sufficient applicability for SHM problems.