PaIRS-UniNa 0.1.11

PaIRS - Particle Image Reconstruction Software

PaIRS-UniNa: Particle Image Reconstruction Software - University of Naples "Federico II"

PaIRS-UniNa is a project developed by the Experimental Thermo Fluid-Dynamics (ETFD) group of University of Naples "Federico II" since 2000. It is aimed to provide fast and efficient tools for digital particle image velocimetry (PIV) analysis in research and industrial applications.

PaIRS-UniNa is based on a C library (PaIRS-PIV) and relies on a graphical user interface (PaIRS) that is developed via PySide6 and makes the use of PaIRS-PIV easy and intuitive. PaIRS-PIV includes several modules that allow to process double-frame or time-resolved 2D planar PIV images as well as stereoscopic and tomographic PIV or Lagrangian particle tracking velocimetry (4D PTV) measurements.

The current release of PaIRS-UniNa features only the module for the 2D planar PIV analysis and a module for optical calibration of camera systems, namely CalVi.

CalVi is the calibration module of PaIRS-UniNa and allows accurate optical calibration of single and multiple camera bundles with the camera models mostly used in the PIV community: polynomials, rational functions and the pinhole camera model. Among the other features, it supports camera calibration procedures working with unknown positions and orientations of the calibration target and the integration of the pinhole camera model with a refractive correction model for cylindrical geometries (based on ray-tracing and Snell’s law).

PaIRS-UniNa is supported by Python 3.8+ and is compatible with all the operating systems, however, the PaIRS-PIV library relies on OpemMP library, which must be installed on the macOS platform. On the other side, PaIRS requires, among other packages, SciPy and matplotlib.

All PaIRS-UniNa wheels are distributed under LGPLv3+ licences. The installation can be performed with:

python -m pip install PaIRS-UniNa

To run PaIRS the following commands can be used in a Python environment:

from PaIRS_UniNa import PaIRS
PaIRS.run()

while to run CalVi the following commands can be used:

from PaIRS_UniNa import CalVi
CalVi.run()

MacOS requirements

Normally the OpenMP library is not preinstalled in MacOs. A possible way to install this library is:

curl -O https://mac.r-project.org/openmp/openmp-12.0.1-darwin20-Release.tar.gz
sudo tar fvxz openmp-12.0.1-darwin20-Release.tar.gz -C /

User guide

For more details about PaIRS usage, see our user guide.

For more details about CalVi usage, see our user guide.

Authors and contact details

Gerardo Paolillo - Research Associate, Department of Industrial Engineering, University of Naples "Federico II", via Claudio, 21, 80125, Napoli, Italy

Tommaso Astarita - Full professor, Department of Industrial Engineering, University of Naples "Federico II", Piazzale Tecchio, 80, 80125, Napoli, Italy

email: [e-mail]

Related works

Please cite the following works if you are intended to use PaIRS-UniNa for your purposes:

[1] Astarita, T., & Cardone, G. (2005). "Analysis of interpolation schemes for image deformation methods in PIV". Experiments in Fluids, 38(2), 233-243. doi: 10.1007/s00348-004-0902-3

[2] Astarita, T. (2006). "Analysis of interpolation schemes for image deformation methods in PIV: effect of noise on the accuracy and spatial resolution". Experiments in Fluids, vol. 40 (6): 977-987. doi: 10.1007/s00348-006-0139-4

[3] Astarita, T. (2007). "Analysis of weighting windows for image deformation methods in PIV." Experiments in Fluids, 43(6), 859-872. doi: 10.1007/s00348-007-0314-2

[4] Astarita, T. (2008). "Analysis of velocity interpolation schemes for image deformation methods in PIV". Experiments in Fluids, 45(2), 257-266. doi: 10.1007/s00348-008-0475-7

[5] Astarita, T. (2009). "Adaptive space resolution for PIV". Experiments in Fluids, 46(6), 1115-1123. doi: 10.1007/s00348-009-0618-5

Please cite the following works if you are intended to use CalVi for your purposes:

[1] Paolillo, G., & Astarita, T. (2020). "Perspective camera model with refraction correction for optical velocimetry measurements in complex geometries". IEEE Transactions on Pattern Analysis and Machine Intelligence, 44(6), 3185-3196. doi: 10.1109/TPAMI.2020.3046467.

[2] Paolillo, G., & Astarita, T. (2021). "On the PIV/PTV uncertainty related to calibration of camera systems with refractive surfaces". Measurement Science and Technology, 32(9), 094006. doi: 10.1088/1361-6501/abf3fc.