On accounting for speckle extinction via DIC and PCA

Digital Image Correlation (DIC) is a full-field measurement technique that generally relies on brightness conservation principles. This work aims to analyze cases in which the speckle pattern vanished after heating, thereby severely altering brightness. Sets of images acquired during 6 experiments were registered and then used obtain optimal sets reference for each time step via Principal Component Analysis (PCA). The proposed methodology significantly reduced gray level residuals provided insight into variations occurred analyzed cases. It was possible study with severe changes by updating image when standard DIC did not converge using PCA states.