GDALBUILDVRT(1) GDAL GDALBUILDVRT(1)

NAME

gdalbuildvrt - Builds a VRT from a list of datasets.

SYNOPSIS

gdalbuildvrt [--help] [--help-general]
[-tileindex <field_name>]
[-resolution {highest|lowest|average|user}]
[-te <xmin> <ymin> <xmax> <ymax>] [-tr <xres> <yres>] [-tap]
[-separate] [-b <band>]... [-sd <n>]
[-allow_projection_difference] [-q]
[-addalpha] [-hidenodata]
[-srcnodata "<value>[ <value>]..."] [-vrtnodata "<value>[ <value>]..."
[-ignore_srcmaskband]
[-nodata_max_mask_threshold <threshold>]
[-a_srs <srs_def>]
[-r {nearest|bilinear|cubic|cubicspline|lanczos|average|mode}]
[-oo <NAME>=<VALUE>]...
[-co <NAME>=<VALUE>]...
[-input_file_list <filename>] [-overwrite]
[-strict | -non_strict]
<output_filename.vrt> <input_raster> [<input_raster>]...

DESCRIPTION

This program builds a VRT (Virtual Dataset) that is a mosaic of the
list of input GDAL datasets. The list of input GDAL datasets can be
specified at the end of the command line, or put in a text file (one
filename per line) for very long lists, or it can be a MapServer
tileindex (see gdaltindex utility). In the later case, all entries in
the tile index will be added to the VRT.

NOTE:
Starting with GDAL 3.9, for virtual mosaic with a very large
number of source rasters (typically hundreds of thousands of
source rasters, or more), it is advised to use the gdaltindex
utility to generate a tile index compatible of the GTI driver.

With -separate, each files goes into a separate band in the VRT
dataset. Otherwise, the files are considered as source rasters of a
larger mosaic and the VRT file has as many bands as one of the input
files.

If one GDAL dataset is made of several subdatasets and has 0 raster
bands, all the subdatasets will be added to the VRT rather than the
dataset itself.

gdalbuildvrt does some amount of checks to assure that all files that
will be put in the resulting VRT have similar characteristics :
number of bands, projection, color interpretation... If not, files
that do not match the common characteristics will be skipped. (This
is only true in the default mode, and not when using the -separate
option)

If there is some amount of spatial overlapping between files, the
order of files appearing in the list of source matter: files that are
listed at the end are the ones from which the content will be
fetched. Note that nodata will be taken into account to potentially
fetch data from less priority datasets, but currently, alpha channel
is not taken into account to do alpha compositing (so a source with
alpha=0 appearing on top of another source will override is content).
This might be changed in later versions.

--help Show this help message and exit

--help-general
Gives a brief usage message for the generic GDAL commandline
options and exit.

-tileindex <field_name>
Use the specified value as the tile index field, instead of
the default value which is 'location'.

-resolution {highest|lowest|average|user}
In case the resolution of all input files is not the same, the
-resolution flag enables the user to control the way the
output resolution is computed.

highest will pick the smallest values of pixel dimensions
within the set of source rasters.

lowest will pick the largest values of pixel dimensions within
the set of source rasters.

average is the default and will compute an average of pixel
dimensions within the set of source rasters.

user must be used in combination with the -tr option to
specify the target resolution.

-tr <xres> <yres>
Set target resolution. The values must be expressed in
georeferenced units. Both must be positive values. Specifying
those values is of course incompatible with
highest|lowest|average values for -resolution option.

-tap (target aligned pixels) align the coordinates of the extent of
the output file to the values of the -tr, such that the
aligned extent includes the minimum extent. Alignment means
that xmin / resx, ymin / resy, xmax / resx and ymax / resy are
integer values.

-te <xmin> <ymin> <xmax> <ymax>
Set georeferenced extents of VRT file. The values must be
expressed in georeferenced units. If not specified, the
extent of the VRT is the minimum bounding box of the set of
source rasters. Pixels within the extent of the VRT but not
covered by a source raster will be read as valid pixels with a
value of zero unless a NODATA value is specified using
-vrtnodata or an alpha mask band is added with -addalpha.

-addalpha
Adds an alpha mask band to the VRT when the source raster have
none. Mainly useful for RGB sources (or grey-level sources).
The alpha band is filled on-the-fly with the value 0 in areas
without any source raster, and with value 255 in areas with
source raster. The effect is that a RGBA viewer will render
the areas without source rasters as transparent and areas with
source rasters as opaque. This option is not compatible with
-separate.

-hidenodata
Even if any band contains nodata value, giving this option
makes the VRT band not report the NoData. Useful when you want
to control the background color of the dataset. By using along
with the -addalpha option, you can prepare a dataset which
doesn't report nodata value but is transparent in areas with
no data.

-srcnodata "<value>[ <value>]..."
Set nodata values for input bands (different values can be
supplied for each band). If more than one value is supplied
all values should be quoted to keep them together as a single
operating system argument. If the option is not specified, the
intrinsic nodata settings on the source datasets will be used
(if they exist). The value set by this option is written in
the NODATA element of each ComplexSource element. Use a value
of None to ignore intrinsic nodata settings on the source
datasets.

-ignore_srcmaskband
New in version 3.3.


Starting with GDAL 3.3, if a source has a mask band
(internal/external mask band, or alpha band), a
<ComplexSource> element is created by default with a
<UseMaskBand>true</UseMaskBand> child element, to instruct the
VRT driver to use the mask band of the source to mask pixels
being composited. This is a generalization of the NODATA
element. When specifying the -ignore_srcmaskband option, the
mask band of sources will not be taken into account, and in
case of overlapping between sources, the last one will
override previous ones in areas of overlap.

-nodata_max_mask_threshold <threshold>
New in version 3.9.


Insert a <NoDataFromMaskSource> source, which replaces the
value of the source with the value of -vrtnodata (or 0 if not
specified) when the value of the mask band of the source is
less or equal to the threshold. This is typically used to
transform a R,G,B,A image into a R,G,B one with a NoData
value.

-b <band>
Select an input <band> to be processed. Bands are numbered
from 1. If input bands not set all bands will be added to
vrt. Multiple -b switches may be used to select a set of
input bands.

-sd <n>
If the input dataset contains several subdatasets, use a
subdataset with the specified number (starting from 1). This
is an alternative of giving the full subdataset name as an
input to the utility.

-vrtnodata "<value>[ <value>]..."
Set nodata values at the VRT band level (different values can
be supplied for each band). If more than one value is
supplied all values should be quoted to keep them together as
a single operating system argument. If the option is not
specified, intrinsic nodata settings on the first dataset will
be used (if they exist). The value set by this option is
written in the NoDataValue element of each VRTRasterBand
element. Use a value of None to ignore intrinsic nodata
settings on the source datasets.

-separate
Place each input file into a separate band. Contrary to the
default mode, it is not required that all bands have the same
datatype.

Starting with GDAL 3.8, all bands of each input file are added
as separate VRT bands, unless -b is specified to select a
subset of them. Before GDAL 3.8, only the first band of each
input file was placed into a new VRT band, and -b was ignored.

-allow_projection_difference
When this option is specified, the utility will accept to make
a VRT even if the input datasets have not the same projection.
Note: this does not mean that they will be reprojected. Their
projection will just be ignored.

-a_srs <srs_def>
Override the projection for the output file. The <srs_def>
may be any of the usual GDAL/OGR forms, complete WKT, PROJ.4,
EPSG:n or a file containing the WKT. No reprojection is done.

-r {nearest|bilinear|cubic|cubicspline|lanczos|average|mode}
Select a resampling algorithm. Nearest is the default

-oo <NAME>=<VALUE>
Dataset open option (format specific)

New in version 2.2.


-co <NAME>=<VALUE>
Specify a VRT driver creation option.

New in version 3.10.


-input_file_list <filename>
To specify a text file with an input filename on each line

-q To disable the progress bar on the console

-overwrite
Overwrite the VRT if it already exists.

-strict
Turn warnings as failures. This is mutually exclusive with
-non_strict, the latter which is the default.

New in version 3.4.2.


-non_strict
Skip source datasets that have issues with warnings, and
continue processing. This is the default.

New in version 3.4.2.

EXAMPLES

+o Make a virtual mosaic from all TIFF files contained in a directory
:

gdalbuildvrt doq_index.vrt doq/*.tif

+o Make a virtual mosaic from files whose name is specified in a text
file :

gdalbuildvrt -input_file_list my_list.txt doq_index.vrt

+o Make a RGB virtual mosaic from 3 single-band input files :

gdalbuildvrt -separate rgb.vrt red.tif green.tif blue.tif

+o Make a virtual mosaic with blue background colour (RGB: 0 0 255) :

gdalbuildvrt -hidenodata -vrtnodata "0 0 255" doq_index.vrt doq/*.tif

C API

This utility is also callable from C with GDALBuildVRT().

AUTHOR

Even Rouault <even.rouault@spatialys.com>

COPYRIGHT

1998-2025

January 8, 2025 GDALBUILDVRT(1)