General functions of Libgpiv

  • Input/output from files or stdin/stdout.
  • Data storage in ASCII format or HDF version 5 format.
  • Parameter search at local directory, home directory or system wide configuration file. If all are absent, hard-coded default values are used.
  • Data visualization by means of gnuplot.

Data Acquition

  • Trigering of lasers and camera by using Real Time Application Interface (RTAI).
  • Recording of images from (IIDC-compliant) IEEE-1394 (Firewire) camera's.

Image interrogation

  • Interrogation at the entire image or at a defined region within the image frames resulting into a displacement field on a rectangular grid.
  • Interrogation at a single arbitrary point, along a vertical or horizontal line.
  • FFT at competetive speed.
  • Arbitrary interrogation area sizes.
  • Global pre-shifting.
  • Linear weighting filter or local pre-shifting (zero offsetting) of the interrogation areas.
  • Forward and central interrogation scheme
  • Adaptive interrogation area sizes to obtain high resolution and dynamic range.
  • Cross and auto correlation.
  • Defining order of correlation peak to be used as estimator.

PIV data validation

  • Enabling and disabling PIV estimators individually or within a rectangular block.
  • Checking on peak-locking effects.
  • Validation on outliers by SNR value or median test.

PIV data post processing

  • Manipulation (flipping, rotating, ..) of the data.
  • Time and spatial scaling
  • Calculation of statistics and subtraction of mean values from estimators.
  • Calculation of vorticity and strain by different differential schemes.

Gerber van der Graaf
email: gerber_graaf AT users DOT sourceforge DOT net

Last modified: Mon Nov 17 09:39:37 CET 2008