r.buildvrt(1grass) GRASS GIS User's Manual r.buildvrt(1grass)
NAME
r.buildvrt - Build a VRT (Virtual Raster) from the list of input
raster maps.
KEYWORDS
raster, mosaic, virtual raster
SYNOPSIS
r.buildvrt
r.buildvrt --help
r.buildvrt [input=name[,name,...]] [file=name] output=name [ti-
tle=phrase] [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags:
--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--ui
Force launching GUI dialog
Parameters:
input=name[,name,...]
Name of input raster files
file=name
Input file with one raster map name per line
output=name [required]
Name for output raster map
title=phrase
Title for resultant raster map
DESCRIPTION
r.buildvrt builds a virtual raster (VRT) that is a mosaic of the list
of input raster maps. The purpose of such a VRT is to provide fast ac-
cess to small subsets of the VRT, also with multiple simultaneous read
requests.
NOTES
r.buildvrt creates a list of raster maps that can be located in differ-
ent mapsets. The output is a read-only link to the original raster maps
which is only valid if the original raster maps remain in the origi-
nally indicated mapset. A VRT can also be built from raster maps regis-
tered with r.external.
Reading the whole VRT is slower than reading the equivalent single
raster map. Only reading small parts of the VRT provides a performance
benefit.
A GRASS virtual raster can be regarded as a simplified version of
GDAL’s virtual raster format. The GRASS equivalent is simpler because
issues like nodata, projection, resolution, resampling, masking are al-
ready handled by native GRASS raster routines.
EXAMPLES
VRT from a DEM in the North Carolina sample dataset
In this exercise a low resolution DEM is resampled to a high resolution
DEM. This is subsequently cut into small tiles and from that a virtual
tile mosaik is created:
# set the computational region to elevation map
g.region raster=elev_state_500m -p
# enforce higher resolution
g.region res=50 -p
# resample the 500 meter DEM to 50 meter resolution
r.resamp.interp input=elev_state_500m output=elev_state_50m method=bilinear
# create tiles from resulting large 50 m elevation map
r.tile input=elev_state_50m output=elev_state_50m_tile_ width=1000 height=1000 overlap=0
# for convenience, dump list of tile names to a file
g.list type=raster pattern=elev_state_50m_tile_* output=tilelist.csv
# build a mosaik as VRT from tile list
r.buildvrt file=tilelist.csv output=elev_state_50m_vrt
SEE ALSO
r.tile, r.patch, r.external
The equivalent GDAL utility gdalbuildvrt
AUTHOR
Markus Metz
Sponsored by mundialis
SOURCE CODE
Available at: r.buildvrt source code (history)
Accessed: unknown
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GRASS 7.8.7 r.buildvrt(1grass)
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