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gpiv_scale(1) [debian man page]

GPIV_SCALE(1)						      General Commands Manual						     GPIV_SCALE(1)

NAME

       gpiv_scale - Scaling of PIV data.

SYNOPSIS

       gpiv_scale [-h | --help] [-p | --print] [-s M |-S M] [-t dT |-T dT] [-v | --version] [-zp x0 y0] [-zv x0 y0] [filename] < stdin > stdout

DESCRIPTION

       gpiv_scale  applies  the  image	magnification and the time between successive recordings to the PIV estimators. This results that particle
       displacements [px] are modified to velocities [m/s] and their positions from [px] to [m]. A physical reference for the positions of the PIV
       data can be applied by means of the image zero-offset option.

       If  filename  is used, the parameters and options to be used for gpiv_scale are subsequently read from the image header (filename.h in case
       of raw binary images) or from the configuration resources (containing the IMG and POST keys). The parameters may be overruled by  the  com-
       mand line options, as explained below.

Options
       -h | --help
	      On-line help.

       -p | --print
	      Prints parameters, command line options and input and output filenames to stdout.  The output is identic of filename.par, in case -f
	      is used.

       -s M   spatial scaling with magnification factor M [m/px]

       -S M   Inverse spatial scaling with magnification factor M [m/px]; returns scaled data to their original magnitudes.

       -v | --version
	      Prints version information on standard output, then exits successfully.

       -t dT  Translates particle displacements into velocities by devising them with the time between subsequent recordings dT [s].

       -T dT  Inverse time scaling. Returns velocities into displacements [px]

       [-z x0 y0]
	      Relates the positions of the observations of velocities/displacements to a physical location in the experiment by image zero offset-
	      ting. x0 y0 denote the physical position of pixel (0,0) in the image.

       filename
	      Input PIV file. Overrides stdin and stdout. The output will be written to filename.sc.piv. Parameters are stored in filename.par and
	      may be used for future use by including them in ./gpivrc.

       SEE ALSO
	      gpivtools

NOTES

AUTHOR

       Gerber Van der Graaf

BUGS

       The program has been tested for PIV data. So far, no bugs have been found.

								  8 November 2006						     GPIV_SCALE(1)

Check Out this Related Man Page

GPIV_PEAKLCK(1) 					      General Commands Manual						   GPIV_PEAKLCK(1)

NAME

       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.

SYNOPSIS

       gpiv_peaklck [-g] [-h | --help] [-n N] [-p | --print] [-v | --version] [filename] < stdin > stdout

DESCRIPTION

       Peak-locking effects in Particle Image Velocimetry (PIV) result into estimations of the particle displacements that are mainly at an  inte-
       ger  number  of	pixels, instead of at sub-pixel displacements. This effect may due to stretching of the (round) pixel images, due to a too
       low resolution of the pixel-image or may be due to signal interferences of the data from camera to frame grabber.  Gpiv_Peaklck	calculates
       the  particle  displacement  distribution at sub-pixel level in between 0.0 an 1.0 (0 included, 1 excluded). If peak locking occurs, a non-
       uniform distribution of the estimated particle displacements at sub-pixel level will be found.

       The configuration parameters (containing the VALID key) may be overruled by the command line options, as explained below.

Options
       -g     Graphical visualization of the histogram with gnuplot.

       -h | --help
	      On-line help

       -n N   Override number of bins (default 10, hard coded).

       -p | --print
	      Print parameters, command line options and eventually used input and output filenames to stdout.	The output  is	identic  of  file-
	      name.par, in case -f is used.

       -v | --version
	      Print version information on standard output, then exit successfully.

       filename
	      Input  PIV data file. Overrides stdin and stdout. Output will be written to filename.plk. The parameters will be written or appended
	      to filename.par and may be used for future use by including them in ./gpivrc.

SEE ALSO

       gpivtools

AUTHOR

       Gerber Van der Graaf

BUGS

       The program seems to work fine with real PIV data.  So far, no serious bugs have been found.

								  8 November 2006						   GPIV_PEAKLCK(1)
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