GPIVTOOLS(1)						      General Commands Manual						      GPIVTOOLS(1)

NAME

       gpivtools - The PIV tool suite.

DESCRIPTION

       gpivtools  is  a  set of command-line driven programs for the so-called Digital Particle Image Velocimetry (DPIV). It contains programs for
       image recording, processing and analysing (resulting into estimators of particle displacement, i.e. PIV data), PIV data validation programs
       and post-processing tools for manipulating and calculating (scalar) derivatives of the PIV data.

       Though the command-line driven tools are mainly intended for non-interactive processing, its outputs may directly be visualized in a graph-
       ical way with the aid of gnuplot.

       The parameters and options to be used for most of the gpivtools are provided by Libgpiv. They are  subsequently	searched  in  ./gpivrc	at
       local  directory, at $HOME/.gpivrc (hidden) or at the system-wide configuration file gpiv.conf, which is mostly found at /etc for UNIX-like
       operating systems. Each parameter is described by the process key: GENPAR (general parameters), CAM (camera settings), TRIG  (trigger  set-
       tings),	IMG (image header), IMGPROC (image processing), PIV (piv interrogation), VALID (piv data validation) or POST (piv post processing)
       and the parameter name, separated by a dot (.), followed by its value. Some of the parameters are optional. The parameters may  be  defined
       in  arbitrary  order.  Blank lines and comment (starting with a pound sign (#) at the first column) may be included in the parameter files.
       The parameters may be overruled by the command line options of each tool. Libgpiv provides default parameter values if they are not defined
       in one of the configuration files or by an option key at the command line.

       In case stdin and stdout is used, verbose output of the programs is suppressed in order to avoid contamination of the output data. If file-
       name is used for overruling stdin and stdout,  the  parameters  are  written  to  filename.par.	By  renaming  this  file  to  ./gpivrc	or
       $HOME/.gpivrc,  the  parameters	may  directly  be  re-used  for identic processing of other images and PIV data. The parameters defined in
       $HOME/.gpivrc and in /etc/gpiv.conf are also used by the Graphic User Interface program gpiv.

       The programs understand different image formats: Portable Network Graphics (filename.png), HDF5	(filename.hdf),  raw  binary  data  (file-
       name.r)	that is accompanied by an ASCII header file (filename.h), and LaVision's (tm) uncompressed image format (filename.img). Other for-
       mats that use lossless compression (TIF, GIF, PGM, BMP) are converted to PNG on the fly. For interrogation of  double-framed  images  using
       cross-correlation,  the second image has to be concatenated after the first one, if this has not already been done by the recording camera.
       This might be performed by gpiv_combing. Image parameters are read from the header or from the configuration resources (containing the  IMG
       key).

GPIV-TOOLS COMMANDS
       Here is the complete list of available gpivtools programs. See their individual man pages for a more extended description.

       gpiv_aint
	      Calculates mean image intensity at each interrogation area.  This program uses the IMG, PIV and POST parameters.

       gpiv_combing
	      Combines two images into one image file for cross-correlation.  This program uses the IMG parameters.

       gpiv_errvec
	      Searches	the  erroneous	vectors in a PIV data file and eventually substitutes them with new values.  This program uses the PIV and
	      POST parameters.

       gpiv_fi-keyline
	      Filters each line that starts with a keyword.  This program does not use the parameter resources from Libgpiv.

       gpiv_hdf2piv
	      Converts hdf5 PIV data (extension .hdf) to ASCII data.  This program does not use the parameter resources from Libgpiv.

       gpiv_imgproc,  gpiv_mktestimg,  gpiv_smooth,  gpiv_hilo,  gpiv_clip,  gpiv_fft,	gpiv_invfft,  gpiv_lowpass,  gpiv_highpass,   gpiv_getbit,
       gpiv_mktestimg
	      (PIV) image processing programs.	These programs use the IMGPROC parameters.

       gpiv_img2gpiv
	      Depreciated:  use  gpiv_combing instead. Converts images into raw data (extension .r) format with the belonging ASCII header (exten-
	      sion .h) or into hdf format (with extension .hdf). This program does not use the parameter resources from Libgpiv.

       gpiv_manipiv, gpiv_fasty, gpiv_flipx, gpiv_flipy, gpiv_revert, gpiv_rot90, gpiv_rot180
	      Simple data manipulation tool for PIV data.  These programs use the POST parameters.

       gpiv_peaklck
	      Tests PIV data on the so-called peak-locking effect by printing/displaying an histogram of the particle displacements  at  sub-pixel
	      level.  This program uses the VALID parameters.

       gpiv_piv2gnuplt
	      Converts	PIV  data  gnuplot  data. Besides this, image interrogation and post-processing programs are able to display their results
	      directly (mostly with the -g option). This program does not use the parameter resources from Libgpiv.

       gpiv_piv2grid
	      Converts PIV data to grid data for generating contour plots with Plotmtv.  This program does not use the	parameter  resources  from
	      Libgpiv.

       gpiv_piv2hdf
	      Converts ASCII PIV data to hdf5 formatted data (extension .hdf).	This program does not use the parameter resources from Libgpiv.

       gpiv_piv2vec
	      Adds header to PIV data for a vector plot with Plotmtv.  This program does not use the parameter resources from Libgpiv.

       gpiv_process-chain
	      Processes  a  pipeline  of Gpiv-tool command's, forming process a chain from image recording, image processing, image interrogation,
	      data validation, data post-processing.  This program does not use the parameter resources from Libgpiv.

       gpiv_recimg
	      captures images from a IIDC-compliant CCD camera with IEE1394 connection.  This program uses the IMG parameters.

       gpiv_rr
	      Interrogates images in order to obtain displacement estimators of particles for (Digital) Particle Image Velocimetry.  This  program
	      uses the PIV and VALID parameters.

       gpiv_sca2gri
	      Converts scalar data from gpiv to grid data for contour plotting with Plotmtv This program does not use the parameter resources from
	      Libgpiv.

       gpiv_scale
	      Spatial and time scaling program for PIV data.  This program uses the IMG and POST parameters.

       gpiv_series
	      Script for (parallel) processing a series of numbered files.  This program does not use the parameter resources from Libgpiv.

       gpiv_suta
	      Subtracts time-avaraged velocities (local mean) from the PIV estimators.	This program does not use  the	parameter  resources  from
	      Libgpiv.

       gpiv_s-avg
	      Spatial statistics of PIV data.  This program uses the POST parameters.

       gpiv_t-avg
	      Calculates time-avaraged mean and rms from a series of PIV data.	This program does not use the parameter resources from Libgpiv.

       gpiv_t-avg-img
	      Calculates time-averaged values from a series of images at each pixel.  This program uses the GENPAR parameters.

       gpiv_t-corr
	      Calculates the velocity correlation as function of time (Eulerian correlation) from a series PIV data sets This program does not use
	      the parameter resources from Libgpiv.

       gpiv_trig
	      Triggers a (double Nd_YAGG) laser on a CCD camera.  This program uses the TRIG parameters.

       gpiv_uhisto
	      Tests PIV data by printing/displaying an histogram of the horizontal particle displacements.  This program uses  the  VALID  parame-
	      ters.

       gpiv_vhisto
	      Tests PIV data by printing/displaying an histogram of the vertical particle displacements.  This program uses the VALID parameters.

       gpiv_vorstra, gpiv_vorty, gpiv_nstrain, gpiv_sstrain
	      Calculates the differential quantities vorticity, shear strain and normal strain from PIV data.  These programs use the POST parame-
	      ters.

SEE ALSO

       gpiv, gpiv_control

AUTHOR

       Gerber Van der Graaf

								   26 March 2008						      GPIVTOOLS(1)