GDAL-RASTER-MOSAIC(1) GDAL GDAL-RASTER-MOSAIC(1)
gdal-raster-mosaic - Build a mosaic
Added in version 3.11.
Usage: gdal raster mosaic [OPTIONS] <INPUT>... <OUTPUT>
Build a mosaic, either virtual (VRT) or materialized.
Positional arguments:
-i, --input <INPUT> Input raster datasets (or specify a @<filename> to point to a file containing filenames) [1.. values] [required]
-o, --output <OUTPUT> Output raster dataset [required]
Common Options:
-h, --help Display help message and exit
--json-usage Display usage as JSON document and exit
--config <KEY>=<VALUE> Configuration option [may be repeated]
-q, --quiet Quiet mode (no progress bar)
Options:
-f, --of, --format, --output-format <OUTPUT-FORMAT> Output format ("GDALG" allowed)
--co, --creation-option <KEY>=<VALUE> Creation option [may be repeated]
--overwrite Whether overwriting existing output is allowed
Mutually exclusive with --append
--append Append as a subdataset to existing output
Mutually exclusive with --overwrite
-b, --band <BAND> Input band(s) (1-based index) [may be repeated]
--absolute-path Whether the path to the input datasets should be stored as an absolute path
--resolution <xres>,<yres>|same|average|common|highest|lowest> Target resolution (in destination CRS units) (default: same)
--bbox <BBOX> Target bounding box as xmin,ymin,xmax,ymax (in destination CRS units)
--target-aligned-pixels Round target extent to target resolution
--src-nodata <SRC-NODATA> Set nodata values for input bands. [1.. values]
--dst-nodata <DST-NODATA> Set nodata values at the destination band level. [1.. values]
--hide-nodata Makes the destination band not report the NoData.
--add-alpha Adds an alpha mask band to the destination when the source raster have none.
--pixel-function <PIXEL-FUNCTION> Specify a pixel function to calculate output value from overlapping inputs. PIXEL-FUNCTION=argmax|argmin|cmul|complex|conj|dB|dB2amp|dB2pow|diff|div|exp|expression|geometric_mean|harmonic_mean|imag|intensity|interpolate_exp|interpolate_linear|inv|log10|max|mean|median|min|mod|mode|mul|norm_diff|phase|polar|pow|real|reclassify|replace_nodata|scale|sqrt|sum
--pixel-function-arg <NAME>=<VALUE> Specify argument(s) to pass to the pixel function [may be repeated]
Advanced Options:
--if, --input-format <INPUT-FORMAT> Input formats [may be repeated]
--oo, --open-option <KEY>=<VALUE> Open options [may be repeated]
This program builds a mosaic of a list of input GDAL datasets, that
can be either a virtual mosaic in the VRT (Virtual Dataset) format,
or in a more conventional raster format such as GeoTIFF.
Wildcards '*', '?' or '['] of VSIGlob() can be used for input dataset
names, even on files located on network file systems such as /vsis3/,
/vsigs/, /vsiaz/, etc. Alternatively if a input dataset name is
prefixed by the @ character, it will be assumed to contain the list
of actual dataset names (one per line) to use as input datasets.
gdal raster mosaic does some checks to ensure that all files that
will be put in the resulting file have similar characteristics:
number of bands, projection, color interpretation, etc. If not, files
that do not match the common characteristics will be skipped.
Starting with GDAL 3.12, a function (e.g., min, mean, median) can be
specified (--pixel-function) to calculate pixel values from
overlapping inputs. If no function is specified, or in earlier
versions, the order of the input list is used to determine priority.
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 lower-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
its content). This might be changed in later versions.
Stating with GDAL 3.12, this command can also be used as the first
step of gdal raster pipeline.
The following options are available:
-f, --of, --format, --output-format <OUTPUT-FORMAT>
Which output raster format to use. Allowed values may be given
by gdal --formats | grep raster | grep rw | sort
--co, --creation-option <NAME>=<VALUE>
Many formats have one or more optional creation options that
can be used to control particulars about the file created. For
instance, the GeoTIFF driver supports creation options to
control compression, and whether the file should be tiled.
May be repeated.
The creation options available vary by format driver, and some
simple formats have no creation options at all. A list of
options supported for a format can be listed with the
--formats command line option but the documentation for the
format is the definitive source of information on driver
creation options. See Raster drivers format specific
documentation for legal creation options for each format.
--overwrite
Allow program to overwrite existing target file or dataset.
Otherwise, by default, gdal errors out if the target file or
dataset already exists.
-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 the
output. Multiple -b switches may be used to select a set of
input bands.
--resolution {<xres,yres>|same|highest|lowest|average}
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.
same, the default, checks that all source rasters have the
same resolution and errors out when this is not the case.
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 will compute an average of pixel dimensions within the
set of source rasters.
common determines the greatest common divisor of the source
pixel dimensions, e.g. 0.2 for source pixel dimensions of 0.4
and 0.6.
<xres>,<yres>. The values must be expressed in georeferenced
units. Both must be positive values.
--absolute-path
Added in version 3.12.0.
When writing a VRT file, enables writing the absolute path of
the input datasets. By default, input filenames are written in
a relative way with respect to the VRT filename (when
possible).
--bbox <xmin>,<ymin>,<xmax>,<ymax>
Set georeferenced extents of output file. The values must be
expressed in georeferenced units. If not specified, the
extent of the output is the minimum bounding box of the set of
source rasters. Pixels within the extent of the output 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
--dst-nodata or an alpha mask band is added with --add-alpha.
--target-aligned-pixels
(target aligned pixels) align the coordinates of the extent of
the output file to the values of the --resolution, such that
the aligned extent includes the minimum extent. Alignment
means that xmin / resx, ymin / resy, xmax / resx and ymax /
resy are integer values.
--src-nodata <value>[,<value>]...
Set nodata values for input bands (different values can be
supplied for each band). 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.
--dst-nodata <value>[,<value>]...
Set nodata values at the output 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 (Example 1). 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.
--add-alpha
Adds an alpha mask band to the output 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.
--hide-nodata
Even if any band contains nodata value, giving this option
makes the output band not report the NoData. Useful when you
want to control the background color of the dataset. By using
along with the --add-alpha option, you can prepare a dataset
which doesn't report nodata value but is transparent in areas
with no data.
--pixel-function
Specify a function name to calculate a value from overlapping
inputs. For a list of available pixel functions, see Built-in
Pixel Functions. If no function is specified, values will be
taken from the last overlapping input.
Added in version 3.12.
--pixel-function-arg
Specify an argument to be provided to a pixel function, in the
format <NAME>=<VALUE>. Multiple arguments may be specified by
repeating this option.
Added in version 3.12.
GDALG OUTPUT (ON-THE-FLY / STREAMED DATASET)
This program supports serializing the command line as a JSON file
using the GDALG output format. The resulting file can then be opened
as a raster dataset using the GDALG: GDAL Streamed Algorithm driver,
and apply the specified pipeline in a on-the-fly / streamed way.
Example 1: Make a virtual mosaic with blue background colour (RGB: 0 0
255)
gdal raster mosaic --hide-nodata --dst-nodata=0,0,255 doq/*.tif doq_index.vrt
Even Rouault <even.rouault@spatialys.com>
1998-2026
March 20, 2026 GDAL-RASTER-MOSAIC(1)
NAME
gdal-raster-mosaic - Build a mosaic
Added in version 3.11.
SYNOPSIS
Usage: gdal raster mosaic [OPTIONS] <INPUT>... <OUTPUT>
Build a mosaic, either virtual (VRT) or materialized.
Positional arguments:
-i, --input <INPUT> Input raster datasets (or specify a @<filename> to point to a file containing filenames) [1.. values] [required]
-o, --output <OUTPUT> Output raster dataset [required]
Common Options:
-h, --help Display help message and exit
--json-usage Display usage as JSON document and exit
--config <KEY>=<VALUE> Configuration option [may be repeated]
-q, --quiet Quiet mode (no progress bar)
Options:
-f, --of, --format, --output-format <OUTPUT-FORMAT> Output format ("GDALG" allowed)
--co, --creation-option <KEY>=<VALUE> Creation option [may be repeated]
--overwrite Whether overwriting existing output is allowed
Mutually exclusive with --append
--append Append as a subdataset to existing output
Mutually exclusive with --overwrite
-b, --band <BAND> Input band(s) (1-based index) [may be repeated]
--absolute-path Whether the path to the input datasets should be stored as an absolute path
--resolution <xres>,<yres>|same|average|common|highest|lowest> Target resolution (in destination CRS units) (default: same)
--bbox <BBOX> Target bounding box as xmin,ymin,xmax,ymax (in destination CRS units)
--target-aligned-pixels Round target extent to target resolution
--src-nodata <SRC-NODATA> Set nodata values for input bands. [1.. values]
--dst-nodata <DST-NODATA> Set nodata values at the destination band level. [1.. values]
--hide-nodata Makes the destination band not report the NoData.
--add-alpha Adds an alpha mask band to the destination when the source raster have none.
--pixel-function <PIXEL-FUNCTION> Specify a pixel function to calculate output value from overlapping inputs. PIXEL-FUNCTION=argmax|argmin|cmul|complex|conj|dB|dB2amp|dB2pow|diff|div|exp|expression|geometric_mean|harmonic_mean|imag|intensity|interpolate_exp|interpolate_linear|inv|log10|max|mean|median|min|mod|mode|mul|norm_diff|phase|polar|pow|real|reclassify|replace_nodata|scale|sqrt|sum
--pixel-function-arg <NAME>=<VALUE> Specify argument(s) to pass to the pixel function [may be repeated]
Advanced Options:
--if, --input-format <INPUT-FORMAT> Input formats [may be repeated]
--oo, --open-option <KEY>=<VALUE> Open options [may be repeated]
DESCRIPTION
This program builds a mosaic of a list of input GDAL datasets, that
can be either a virtual mosaic in the VRT (Virtual Dataset) format,
or in a more conventional raster format such as GeoTIFF.
Wildcards '*', '?' or '['] of VSIGlob() can be used for input dataset
names, even on files located on network file systems such as /vsis3/,
/vsigs/, /vsiaz/, etc. Alternatively if a input dataset name is
prefixed by the @ character, it will be assumed to contain the list
of actual dataset names (one per line) to use as input datasets.
gdal raster mosaic does some checks to ensure that all files that
will be put in the resulting file have similar characteristics:
number of bands, projection, color interpretation, etc. If not, files
that do not match the common characteristics will be skipped.
Starting with GDAL 3.12, a function (e.g., min, mean, median) can be
specified (--pixel-function) to calculate pixel values from
overlapping inputs. If no function is specified, or in earlier
versions, the order of the input list is used to determine priority.
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 lower-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
its content). This might be changed in later versions.
Stating with GDAL 3.12, this command can also be used as the first
step of gdal raster pipeline.
Options
The following options are available:
-f, --of, --format, --output-format <OUTPUT-FORMAT>
Which output raster format to use. Allowed values may be given
by gdal --formats | grep raster | grep rw | sort
--co, --creation-option <NAME>=<VALUE>
Many formats have one or more optional creation options that
can be used to control particulars about the file created. For
instance, the GeoTIFF driver supports creation options to
control compression, and whether the file should be tiled.
May be repeated.
The creation options available vary by format driver, and some
simple formats have no creation options at all. A list of
options supported for a format can be listed with the
--formats command line option but the documentation for the
format is the definitive source of information on driver
creation options. See Raster drivers format specific
documentation for legal creation options for each format.
--overwrite
Allow program to overwrite existing target file or dataset.
Otherwise, by default, gdal errors out if the target file or
dataset already exists.
-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 the
output. Multiple -b switches may be used to select a set of
input bands.
--resolution {<xres,yres>|same|highest|lowest|average}
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.
same, the default, checks that all source rasters have the
same resolution and errors out when this is not the case.
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 will compute an average of pixel dimensions within the
set of source rasters.
common determines the greatest common divisor of the source
pixel dimensions, e.g. 0.2 for source pixel dimensions of 0.4
and 0.6.
<xres>,<yres>. The values must be expressed in georeferenced
units. Both must be positive values.
--absolute-path
Added in version 3.12.0.
When writing a VRT file, enables writing the absolute path of
the input datasets. By default, input filenames are written in
a relative way with respect to the VRT filename (when
possible).
--bbox <xmin>,<ymin>,<xmax>,<ymax>
Set georeferenced extents of output file. The values must be
expressed in georeferenced units. If not specified, the
extent of the output is the minimum bounding box of the set of
source rasters. Pixels within the extent of the output 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
--dst-nodata or an alpha mask band is added with --add-alpha.
--target-aligned-pixels
(target aligned pixels) align the coordinates of the extent of
the output file to the values of the --resolution, such that
the aligned extent includes the minimum extent. Alignment
means that xmin / resx, ymin / resy, xmax / resx and ymax /
resy are integer values.
--src-nodata <value>[,<value>]...
Set nodata values for input bands (different values can be
supplied for each band). 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.
--dst-nodata <value>[,<value>]...
Set nodata values at the output 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 (Example 1). 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.
--add-alpha
Adds an alpha mask band to the output 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.
--hide-nodata
Even if any band contains nodata value, giving this option
makes the output band not report the NoData. Useful when you
want to control the background color of the dataset. By using
along with the --add-alpha option, you can prepare a dataset
which doesn't report nodata value but is transparent in areas
with no data.
--pixel-function
Specify a function name to calculate a value from overlapping
inputs. For a list of available pixel functions, see Built-in
Pixel Functions. If no function is specified, values will be
taken from the last overlapping input.
Added in version 3.12.
--pixel-function-arg
Specify an argument to be provided to a pixel function, in the
format <NAME>=<VALUE>. Multiple arguments may be specified by
repeating this option.
Added in version 3.12.
GDALG OUTPUT (ON-THE-FLY / STREAMED DATASET)
This program supports serializing the command line as a JSON file
using the GDALG output format. The resulting file can then be opened
as a raster dataset using the GDALG: GDAL Streamed Algorithm driver,
and apply the specified pipeline in a on-the-fly / streamed way.
EXAMPLES
Example 1: Make a virtual mosaic with blue background colour (RGB: 0 0
255)
gdal raster mosaic --hide-nodata --dst-nodata=0,0,255 doq/*.tif doq_index.vrt
AUTHOR
Even Rouault <even.rouault@spatialys.com>
COPYRIGHT
1998-2026
March 20, 2026 GDAL-RASTER-MOSAIC(1)