Provided by: gdal-bin_3.8.4+dfsg-3ubuntu3_amd64 
NAME
gdal_calc - Command line raster calculator with numpy syntax.
SYNOPSIS
gdal_calc.py [--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).
--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 aritmethic 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.
EXAMPLE
Add two files together:
gdal_calc.py -A input1.tif -B input2.tif --outfile=result.tif --calc="A+B"
Average of two layers:
gdal_calc.py -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.py -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.py -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="A+B+C"
New in version 3.3.
gdal_calc.py -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.py -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="(A+B+C)/3"
New in version 3.3.
gdal_calc.py -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.py -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="numpy.max((A,B,C),axis=0)"
New in version 3.3.
gdal_calc.py -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.py -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.py -A input.tif --outfile=result.tif --calc="A*logical_and(A>100,A<150)"
Work with multiple bands:
gdal_calc.py -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
1998-2024
Feb 08, 2024 GDAL_CALC(1)