Full-field correlation-based image processing for PIV

Due to its high robustness, correlation-based particle image velocimetry (PIV) has become the prime choice for processing image-based flow measurements in fluid dynamics experiments. However, in recent years, whole-field techniques like optical flow methods have been successfully applied to this kind of images. To avoid the dependence of optical flow methods on intensity variations and to combine the robustness of the correlation-based PIV technique with the whole-field flow description of the optical flow method, a hybrid estimation procedure has been developed. It is an iterative method, optimizing a dense, hypothetical velocity field with respect to vanishing residual displacements, obtained by image correlation