gpiv_scale (1)

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

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 command line options, as explained below.

-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 offsetting. 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.

gpivtools

Gerber Van der Graaf

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