i.gcp - GRASS GIS manual

Note: This document is for an older version of GRASS GIS that has been discontinued. You should upgrade, and read the current manual page.

NAME

i.gcp - Manages Ground Control Points (GCPs) non-interactively.

KEYWORDS

imagery, georectification, GCP

SYNOPSIS

i.gcp

i.gcp --help

i.gcp [-lcduibrLB] group=name [image_coordinates=east,north] [target_coordinates=east,north] [status=string] [point=integer[,integer,...]] [--help] [--verbose] [--quiet] [--ui]

Flags:

-l: List all ground control points
-c: Clear all ground control points
-d: Delete selected ground control points
-u: Use selected ground control points
-i: Ignore selected ground control points
-b: Back up the point file
-r: Restore the backup point file
-L: List all ground control points in the backup point file
-B: Remove the backup point file
--help: Print usage summary
--verbose: Verbose module output
--quiet: Quiet module output
--ui: Force launching GUI dialog

Parameters:

group=name [required]: Name of input imagery group
image_coordinates=east,north: Image coordinates to add
target_coordinates=east,north: Target coordinates to add
status=string: Status for new ground control points; Options: use, ignore; Default: use
point=integer[,integer,...]: Point number(s) to manage; Options: 1-

DESCRIPTION
NOTES
EXAMPLES
SEE ALSO
AUTHOR

DESCRIPTION

i.gcp manages Ground Control Points (GCPs) non-interactively.

NOTES

Unlike g.gui.gcp, i.gcp can be invoked from the command line or scripts to manage GCPs. It is recommended to create a backup copy of the original POINTS file using -b before making changes to the file. The backup POINTS file (POINTS_BAK) can be restored using -r or removed later using -B. GCPs in the backup POINTS file can be listed using -L.

EXAMPLES

List all GCPs in group "sar":

i.gcp -l group=sar

Create a backup copy of the current POINTS file:

i.gcp -b group=sar

Clear all GCPs first by removing the POINTS file:

i.gcp -c group=sar

Add new GCPs at the bottom-left and top-right corners of the satellite imagery:

i.gcp group=sar image_coordinates=0,0,31996,32239 target_coordinates=493920,3880490,529470,3916310

Add another GCP that will be ignored for now and list all GCPs:

i.gcp -l group=sar image_coordinates=100,100 target_coordinates=500000,4000000 status=ignore

Use the GCP just added and list all:

i.gcp -u -l group=sar point=3

Delete point 1:

i.gcp -d -l group=sar point=1

Ignore points 1-2:

i.gcp -i -l group=sar point=1-2

List GCPs in the backup POINTS file:

i.gcp -L group=sar

Restore the backup POINTS file:

i.gcp -r group=sar

Remove the backup POINTS file:

i.gcp -B group=sar

AUTHOR

Huidae Cho

SOURCE CODE

Available at: i.gcp source code (history)

Latest change: Monday Jun 28 07:54:09 2021 in commit: 1cfc0af029a35a5d6c7dae5ca7204d0eb85dbc55