TecPIV-A MATLAB-based application for PIV-analysis of experimental tectonics

TecPIV is a MATLAB-based, open source application aiming to facilitate and accelerate the Particle Image Velocimetry (PIV) analysis of analogue tectonic models. Since tectonic modelling experiments are usually slow, low sensitivity but high resolution digital cameras can be employed to monitor displacements and calculate strain from PIV analysis. The presented work-flow package provides an integrated environment to import raw files, calibrate, enhance, undistort and rectify the views of the model, calculate the incremental displacements between successive images, the spatial derivatives, and the Eulerian cumulative displacements. The calibration procedure employs a combination of linear and polynomial functions allowing correction of both lens and parallax distortions. The cross-correlation uses a parallelized FFT-method to accelerate the processing of large images. The performance is tested using synthetic images designed to evaluate the precision of the produced velocity field for various settings as well as the ability to capture sharp features characteristic of experimental tectonics.