Profile: Gpiv C.S.

Contributed by Gerber van der Graaf

Gpiv C.S. is a free/open source program for Particle Image Velocimetry (PIV), which analyzes the positions of particles in a video in order to calculate their velocity distribution over time and space. It can quantitatively measure the flow of fluids or deformation of solids, or for any other purpose involving the deformation of an image texture over time. For example, Gpiv turns video of tracer particles in water, tiny bubbles in transparent molten plastics, even texture on a solid surface, into a set of maps of displacements and velocities over time.

Gpiv screenshot

The Gpiv package includes a graphical user interface (GUI) through which the user can set all of the parameters (for image processing, image interrogation, PIV-data validation and PIV post-processing), run any of its calculations, and display the resulting data. For non-interactive or background processing, the Gpivtools package provides more than forty command-line programs, scripts, and additional tools. The Libgpiv library provides the majority of the Gpiv and Gpivtools functions, and has a Python wrapper called PyGpiv, so users can write their own programs or Python scripts to extend the functionality of the software as needed.

Gpiv uses state-of-the-art image interrogation and data validation algorithms. The project participated in the world-wide PIV challenge project [1]. And newer methods implemented since the challenge result in even better accuracies of the PIV estimators. A few of those include: image deformation, adaptive grid and interrogation area dimensions, PIV-data validation during the iterative interrogation using normalized residus from SNR values or from the median test, and Symetric Phase Only Filtering.

Finally, Gpiv developers have recently modified the code to run in parallel on multi-CPU computer systems and clusters, using OpenMP and MPI. This dramatically improves the speed of image interrogation, particularly for large PIV image sets. You can read a complete list of Gpiv features at

[1] Stanislas et al., "Main results of the third international PIV challenge," Exp. Fluids 45(1):27-71 (July 2008), DOI 10.1007/s00348-008-0462-z.

The text and image content on this page is Copyright 2008 Gerber van der Graaf; formatting is Copyright 2008 Opennovation; you may redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

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