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UVMAT - browsing images and velocity fields using Matlab

UVMAT - Free Matlab GUI for PIV

UVMAT is a set of Matlab functions and user interfaces for Particle Imaging Velocimetry with tools for scanning images and data files (vectors and scalars), geometric calibrations, image pre-processing and analysis of time series. It is designed to favor data management, relying on the standard NetCDF file format and xml documentation files.

This free Matlab toolbox (GNU GPL licence) contains a PIV program under Matlab and a graphic user interface to run other programs, like the Correlation Image Velocimetry software CIVx. Tools are provided to run programs on a computer cluster with different file administration systems (SGE, OAR, Slurm...)

Read more about UVMAT on our forge.

CIVx - free code for image velocimetry

CIVx (Correlation Imaging Velocimetry) is a free advanced Imaging Velocimetry implementation of Direct-Cross Correlation PIV that relies on generalized pattern matching by direct cross-correlation of pattern boxes between image pairs. The source code, written in Fortran, can be downloaded from source forge. CIVx is portable to most computer architectures and operating systems. The binary executable files, compiled for several systems (Linux, win32, MacOS) can be downloaded with the package UVMAT.

The Matlab interface uvmat has been developed to run this code, analyse data and perform image preprocessing and geometric calibration.

The following documents provide introduction to PIV techniques used in our Coriolis facility. Note that although the general principles remain valid, references to software are outdated, see the UVMAT online help for updates.

Particle Imaging velocimetry at the Coriolis facility, J. Sommeria (2003)
Course on PIV, Hydralab meeting, J. Sommeria (2008)
Vélocimétrie par Imagerie de Particules (présentation à Météo-France, G. Delerce, 12/2000)

Key features of CIVx

- Spatial decoupling of the pattern box in image a from its counterpart in image b
- Arbitrary grid definition by user or mesh generator
- Advanced mask implementation
- Correlation multiplication to reduce spurious vectors
- Iterative CIV, taking into account pattern deformation by strain and rotation.
- Adaptative continuous window shifting to reduce peak-locking effect
- Image distortion
- Numerical computation can be used as first guess
- Standard file format for easy integration with third party solutions.
- User defined criterions for false vector removal
- Graphical User Interface for automatic distribution of large number of jobs over a network of workstations.


- Fincham, A., and G. Spedding, 1997, Low cost, high resolution DPIV for measurement of turbulent fluid flow. Exp. Fluids, 23, 449-462 defined the CIV techniques and several acquisition optimizations.
- Fincham A. and Delerce G. (2000) , Advanced optimization of correlation imaging velocimetry algorithms, Experiments in Fluids 29, S13-S22. describe the latest improvements around a hierarchical scheme and images spatial transformations.

Links for other free PIV software

- mpiv : Matlab toolbox for educational and research purpose. The developers’ intention is to keep the codes short and simple.
- PIVlab : Another simple Matlab toolbox for PIV.
- OpenPIV : Successor of URAPIV, is an initiative to develop open source software for PIV, using Matlab, Python and C++ executables.
- pivmat : Matlab toolbox for post-processing PIV data and turbulence analysis
- pivchallenge : Reference images for testing PIV software