Metrology of Contours by the Virtual Image Correlation Technique

Abstract

The Virtual Image Correlation (VIC) technique consists in finding the optimal fit between a contour or silhouette embedded in an image and a contour or silhouette described from an analytical description in a virtual image. The optical parameters of the virtual image are obtained thanks to a minimization process. The sub-pixel precision and the robustness of the method are shown onto practical experiments. Examples of use are given in the fields of strain measurement, metrology of engineered parts, mechanical testing and metrology of highly deformable inflatable structures. In that last case, the analytical description of contour in the virtual image is obtained from the Timoshenko beam theory relevant of inflatable structures.