---
name: "gpiv_scale"
section: "1"
platform: "linux"
package: "gpivtools"
version: "0.6.0-3.1"
release: "Debian 8 (Jessie)"
platforms: ["linux"]
url: "https://new.carta.tech/gpiv_scale"
---

# gpiv\_scale(1)

Scaling of PIV data.

## 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 command 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 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

  ## SEE ALSO

## NOTES

## AUTHOR

Gerber Van der Graaf

## BUGS

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