Measurement of transient deformation by color encoding

Abstract

We present a method based on color encoding for measurement of transient 3D deformation in diffuse objects. The object is illuminated by structured light that consists of a fringe pattern with cyan fringes embedded in a white background. Color images are registered and information on each color channel is then separated. Surface features appear on the blue channel while fringes on the red channel. The in-plane components of displacement are calculated via digital correlation of the texture images. Likewise, the resulting fringes serve for the measuring of the out-of-plane component. As crossing of information between signals is avoided, the accuracy of the method is high. This is confirmed by a series of displacement measurements of an aluminum plate.

Assessing Cardiac Dynamics based on X-Ray Coronary Angiograms

“…In the further related work, we will use color encoding technique [18] to describe epicardial regions at risk and corresponding deformations.…”

RGB Colour Encoding Improvement for Three-Dimensional Shapes and Displacement Measurement Using the Integration of Fringe Projection and Digital Image Correlation

“…In fact, an alternative technique to 3D-DIC combining 2D-DIC and FP was investigated by previous researchers [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ], but they were usually limited to static testing, a specific size of specimens or presented some errors in the measurement. Nonetheless, the authors of this work proposed a new integration methodology to measure large 3D shapes and displacements in solids [ 39 , 40 ].…”

“…One of the most important issues in this integration is the distortion of in-plane displacements due to 3D surfaces or out-of-plane displacements. This aspect was neglected by some previous authors, and others tried to minimize it by employing telecentric lenses [ 31 ]. The authors of the current work developed a more practical optical correction which also resulted into a more economical and user-friendly solution and a feasible alternative method to 3D-DIC [ 39 ].…”

Dynamic Displacements Measurement Employing Fringe Projection and Digital Image Correlation

“…Specifically, a combination of Fringe Projection (FP) [1] and 2D Digital Image Correlation (2D DIC) [2] using a single camera has been employed to simultaneously measure in-plane and out-of-plane displacements during different dynamic events such an impact and vibration analysis. This approach has been adopted in the past by several authors, including Mares et al [3] who highlighted that if a telecentric lens is not employed the combination of both techniques is not straightforward since the in-plane displacements measured with 2D DIC are sensitive to the out-of-plane displacements experienced by the object during deformation. Thus, in-plane displacements measured using 2D DIC should be corrected using the out-of-plane displacements inferred using the FP technique.…”