.TH GPIV 1 "14 December 2007" .SH NAME gpiv \- Analyzes images obtained from a fluid flow by Particle Image Velocimetry. .SH SYNOPSIS \fBgpiv\fP [\fB-? | --help\fR] [\fB--usage\fR] [\fB--console_bins \fIBINS\fR] [\fB--console_tooltips\fR] [\fB--console_view_gpivbuttons\fR] [\fB--console_view_tabulator\fR] [\fB--display_background \fIINT\fR] [\fB--display_intregs\fR] [\fB--display_piv\fR] [\fB--display_stretch\fR] [\fB--display_scalar \fIINT\fR] [\fB--display_vectorscale \fISCALE\fR] [\fB--display_view_menubar\fR] [\fB--display_view_rulers\fR] [\fB--display_zoomscale \fISCALE\fR] [\fB--hdf\fR] [\fB--img_fmt\fR] [\fB--mpi_nodes] [\fB-p\fR | \fB--print\fR] [\fB--process_imgproc\fR] [\fB--process_piv\fR] [\fB--process_gradient\fR] [\fB--process_resstatst\fR] [\fB--process_errvec\fR] [\fB--process_peaklock\fR] [\fB--process_average\fR] [\fB--process_scale\fR] [\fB--process_substract\fR] [\fB--process_vorstra\fR] [\fIIMAGE1\fR, \fIIMAGE2\fR, \fI...\fR] \fP .SH DESCRIPTION \fBGpiv\fP is a Graphic User Interface program for recording and analyzing images obtained from a fluid flow that has been seeded with tracer particles by the so-called Particle Image Velocimetry (PIV) technique. It allows to have a quick overview of the process settings, easily changing them, executing the processes, visualizing and optimizing their results in an interactive way. The processes that may be performed are image recording, interrogation (resulting into PIV estimators), validation and post-processing of the PIV estimators. The settings for the PIV processes are subsequently searched in \fI~/.gpivrc\fR or in \fIgpiv.conf\fP (system wide), which is provided by libgpiv. For recording images, \fBgpiv\fP recognizes (CCD) cameras that are IIDC-compliant and connected to the Computer with the IEEE1394 or Firewire protocol. In case \fBgpiv\fP will trigger a camera and lasers, it uses a kernel module gpivtrig_rtl from the gpivtrig package that depends on the Real Time Application Interface (RTAI) and RealTimeLinux. Trigger pulses are send to the parallel port of the Computer (/dev/lpt0 or /dev/lpt1; see the configure script of the gpivtrig package) at bins #1 (camera), #2 and #3 (first and second laser respectively). The program may be started directly if all modules have been loaded or by the gpiv_control script, also included in the gpivtrig package, which takes care of the loading and unloading of the needed kernel modules. Currently, the trigger system is tested with RTAI-3.1 and the linux kernel-2.4.27. The parameters and options to be used for \fBgpiv\fP are obtained from ~/.gnome2/gpiv or default settings are to be used if absent. The settings may be changed or updated by menu->settings->preferences. The parameters of \fBgpiv\fP (not the PIV process settings) may be overruled by the command line options, as explained below. When \fBgpiv\fR is used on a (Beowulf, distributed memory) cluster, the MPI-parallelised program \fBgpiv_rr\fR from the gpivtools package is invoked using \fBmpirun\fR. The \fBgpiv\fR program, however, is launched in the normal way, without invoking\fB mpirun\fR. .SH Options .TP \fB-? | --help\fR On-line help. Besides the options of \fBgpiv\fP it also shows the additional GNOME, GTK and GNOME GUI options. .TP \fB--usage\fR Display a brief usage message. .TP \fB--console_bins \fIBINS\fR Number of bins for histograms of estimators at sub-pixel level, performed by the peaklock process and of the median residues, performed by the errvec process. .TP \fB-t\fR | \fB--console_tooltips\fR Show tooltips. .TP \fB--console_view_gpivbuttons\fR View the \fBgpiv\fR buttons of the application. .TP \fB--console_view_tabulator\fR View the tabulator of the application containing all PIV process settings. .TP \fB--display_background \fIINT\fR Displaying of background: \fIINT\fR = 0: darkblue \fIINT\fR = 1: black \fIINT\fR = 2: first frame of image \fIINT\fR = 3: second frame of image .TP \fB--display_intregs\fR Enables displaying of interrogation regions. .TP \fB--display_piv\fR Displaying of PIV data. .TP \fB--display_stretch\fR Enables automatic stretching of the display when zooming. .TP \fB--display_scalar \fIINT\fR Display derived quantities from PIV data: \fIINT\fR = 0: none \fIINT\fR = 1: vorticity \fIINT\fR = 2: shear strain \fIINT\fR = 3: normal strain .TP \fB--display_view_menubar\fR Enables displaying of the menubar. .TP \fB--display_view_rulers\fR Enables displaying of the ruler. .TP \fB--display_vectorscale \fISCALE\fR Display vector with index: \fISCALE\fR = 0: magnification factor = 1, \fISCALE\fR = 1: magnification factor = 2, \fISCALE\fR = 2: magnification factor = 4, \fISCALE\fR = 3: magnification factor = 8, \fISCALE\fR = 4: magnification factor = 16, \fISCALE\fR = 5: magnification factor = 32, \fISCALE\fR = 3: magnification factor = 64, \fISCALE\fR = 4: magnification factor = 128, \fISCALE\fR = 5: magnification factor = 256. .TP \fB-z\fR | \fB--display_zoomscale \fISCALE\fR Display zoom with index: \fISCALE\fR = 0: magnification factor = 0.5, \fISCALE\fR = 1: magnification factor = 0.83, \fISCALE\fR = 2: magnification factor = 1.0, \fISCALE\fR = 3: magnification factor = 1.3, \fISCALE\fR = 4: magnification factor = 1.6, \fISCALE\fR = 5: magnification factor = 2.0. .TP \fB--hdf\fR Save data in HDF5 format with \fB.gpi\fR extension. .TP \fB--img_fmt \fIINT\fR store (modified) image data and header in: \fIINT\fR = 0: PNG format, \fIINT\fR = 1: raw format, \fIINT\fR = 2: HDF5 format, included with the resulting PIV and post-processing data with \fB.gpi\fR extension. .TP \fB--mpi_nodes \fIINT\fR To define the number of nodes when used on a cluster. Used by \fBmpirun -np \fIINT\fR. .TP \fB-p\fR | \fB--print\fR Print process parameter settings to stdout. .TP \fB--process_imgproc\fR Includes image processing in the chain-process. .TP \fB--process_piv\fR Includes piv interrogation in the chain-process. .TP \fB--process_gradient\fR Includes testing on the displacement gradient within interrogation area in the chain-process. .TP \fB--process_resstatst\fR Includes calculation of statistics of displacement residuals in the chain-process. .TP \fB--process_errvec\fR Includes validation on PIV data in the chain-process. .TP \fB--process_peaklock\fR Includes peak lock in the chain- process. .TP \fB--process_average\fR Includes calculation of the whole field average PIV displacements in the chain-process. .TP \fB--process_scale\fR Includes scaling in the chain-process. .TP \fB--process_subtract\fR Includes substracting of the whole field average PIV displacements in the chain-process. .TP \fB--process_vorstra\fR Includes calculation of vorticity in the chain-process. .TP \fIIMAGE1\fR, \fIIMAGE2\fR, \fI...\fR Loads \fIIMAGE1\fR, \fIIMAGE2\fR, ... from a file or from an URI using the Gnome Virtual File System. The maximum allowed image dimensions and quantity to be loaded are defined by the program as described in gpiv_gui.h or by the 'configure' script during the building of \fBgpiv\fR. .SH SEE ALSO On-line documentation at http://gpiv.sourceforge.net/gpiv_doc/index.html or from the help-menu of \fBgpiv\fR, gpiv_control(1) and gpivtools(1). .SH AUTHOR Gerber Van der Graaf