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Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon 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-

Table of contents

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

SEE ALSO

The GRASS 4 Image Processing manual

i.group, i.target, i.rectify, i.points.auto, Ground Control Points Manager

AUTHOR

Huidae Cho

SOURCE CODE

Available at: i.gcp source code (history)

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


Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.

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© 2003-2022 GRASS Development Team, GRASS GIS 7.8.8dev Reference Manual