GDAL_CALC(1) GDAL GDAL_CALC(1)
NAME
gdal_calc - Command line raster calculator with numpy syntax.
SYNOPSIS
gdal_calc [--help] [--help-general]
--calc=expression --outfile=<out_filename> [-A <filename>]
[--A_band=<n>] [-B...-Z <filename>] [<other_options>]
DESCRIPTION
Command line raster calculator with numpy syntax. Use any basic
arithmetic supported by numpy arrays such as
+,
-,
*, and
/ along
with logical operators such as
>. Note that all files must have the
same dimensions (unless extent option is used), but no projection
checking is performed (unless projectionCheck option is used).
NOTE: gdal_calc is a Python utility, and is only available if GDAL
Python bindings are available.
--help Show this help message and exit
--help-general Gives a brief usage message for the generic GDAL commandline
options and exit.
--calc=<expression> Calculation in numpy syntax using
+,
-,
/,
*, or any numpy
array functions (i.e.
log10()). Multiple
--calc options can
be listed to produce a multiband file (GDAL >= 3.2).
-A <filename> Input gdal raster file, you can use any letter (a-z, A-Z).
(lower case supported since GDAL 3.3)
A letter may be repeated, or several values (separated by
space) can be provided (GDAL >= 3.3). Since GDAL 3.5,
wildcard exceptions (using ?, *) are supported for all
shells/platforms. The effect will be to create a 3-dim numpy
array. In such a case, the calculation formula must use this
input as a 3-dim array and must return a 2D array (see
examples below). In case the calculation does not return a 2D
array an error would be generated.
--A_band=<n> Number of raster band for file A (default 1).
--outfile=<filename> Output file to generate or fill.
--NoDataValue=<value> Output NoDataValue (default datatype specific value). To
indicate not setting a NoDataValue use --NoDataValue=none
(GDAL >= 3.3)
NOTE: Using the Python API:
None value will indicate default
datatype specific value.
'none' value will indicate not
setting a NoDataValue.
--hideNoData New in version 3.3.
Ignores the input bands NoDataValue. By default, the input
bands NoDataValue are not participating in the calculation.
By setting this setting - no special treatment will be
performed on the input NoDataValue. and they will be
participating in the calculation as any other value. The
output will not have a set NoDataValue, unless you explicitly
specified a specific value by setting --NoDataValue=<value>.
--type=<datatype> Output datatype, must be one of [
Byte,
Int8,
UInt16,
Int16,
UInt32,
Int32,
UInt64,
Int64,
Float64,
Float32,
CInt16,
CInt32,
CFloat64,
CFloat32].
NOTE: Despite the datatype set using
--type, when doing
intermediate arithmetic operations using operands of the
same type, the operation result will honor the original
datatype. This may lead into unexpected results in the
final result.
NOTE: UInt64, Int64, CInt16, CInt32, CFloat32, CFloat64 have been
added in GDAL 3.5.3 Int8 has been added in GDAL 3.7
--format=<gdal_format> GDAL format for output file.
--color-table=<filename> Allows specifying a filename of a color table (or a ColorTable
object) (with Palette Index interpretation) to be used for the
output raster. Supported formats: txt (i.e. like gdaldem, but
color names are not supported), qlr, qml (i.e. exported from
QGIS)
--extent=<option> New in version 3.3.
This option determines how to handle rasters with different
extents. This option is mutually exclusive with the
projwin option, which is used for providing a custom extent.
For all the options below the pixel size (resolution) and SRS
(Spatial Reference System) of all the input rasters must be
the same.
ignore (default) - only the dimensions of the rasters are
compared. if the dimensions do not agree the operation will
fail.
fail - the dimensions and the extent (bounds) of the rasters
must agree, otherwise the operation will fail.
union - the extent (bounds) of the output will be the minimal
rectangle that contains all the input extents.
intersect - the extent (bounds) of the output will be the
maximal rectangle that is contained in all the input extents.
--projwin <ulx> <uly> <lrx> <lry> New in version 3.3.
This option provides a custom extent for the output, it is
mutually exclusive with the
extent option.
--projectionCheck New in version 3.3.
By default, no projection checking will be performed. By
setting this option, if the projection is not the same for all
bands then the operation will fail.
--creation-option=<option> Passes a creation option to the output format driver.
Multiple options may be listed. See format specific
documentation for legal creation options for each format.
--co=<option> The same as
creation-option.
--allBands=[a-z, A-Z] Process all bands of given raster (a-z, A-Z). Requires a
single calc for all bands.
--overwrite Overwrite output file if it already exists. Overwriting must
be understood here as deleting and recreating the file from
scratch. Note that if this option is
not specified and the
output file already exists, it will be updated in place.
--debug Print debugging information.
--quiet Suppress progress messages.
PYTHON OPTIONS
New in version 3.3.
The following options are available by using function the python
interface of gdal_calc. They are not available using the command
prompt.
user_namespace A dictionary of custom functions or other names to be
available for use in the Calc expression.
return_ds If enabled, the output dataset would be returned from the
function and not closed.
color_table Allows specifying a ColorTable object (with Palette Index
interpretation) to be used for the output raster.
EXAMPLES
Add two files together:
gdal_calc -A input1.tif -B input2.tif --outfile=result.tif --calc="A+B"
Average of two layers:
gdal_calc -A input1.tif -B input2.tif --outfile=result.tif --calc="(A+B)/2"
NOTE: In the previous example, beware that if A and B inputs are of the
same datatype, for example integers, you may need to force the
conversion of one of the operands before the division operation.
gdal_calc -A input.tif -B input2.tif --outfile=result.tif --calc="(A.astype(numpy.float64) + B) / 2"
Add three files together (two options with the same result):
gdal_calc -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="A+B+C"
gdal_calc -A input1.tif -A input2.tif -A input3.tif --outfile=result.tif --calc="numpy.sum(A,axis=0)".
Average of three layers (two options with the same result):
gdal_calc -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="(A+B+C)/3"
gdal_calc -A input1.tif input2.tif input3.tif --outfile=result.tif --calc="numpy.average(a,axis=0)".
Maximum of three layers (two options with the same result):
gdal_calc -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="numpy.max((A,B,C),axis=0)"
gdal_calc -A input1.tif input2.tif input3.tif --outfile=result.tif --calc="numpy.max(A,axis=0)"
Set values of zero and below to null:
gdal_calc -A input.tif --outfile=result.tif --calc="A*(A>0)" --NoDataValue=0
Using logical operator to keep a range of values from input:
gdal_calc -A input.tif --outfile=result.tif --calc="A*logical_and(A>100,A<150)"
Work with multiple bands:
gdal_calc -A input.tif --A_band=1 -B input.tif --B_band=2 \
--outfile=result.tif --calc="(A+B)/2" --calc="B*logical_and(A>100,A<150)"
AUTHOR
Chris Yesson <chris dot yesson at ioz dot ac dot uk>, Etienne
Tourigny <etourigny dot dev at gmail dot com>
COPYRIGHT
1998-2025
January 8, 2025 GDAL_CALC(1)
