1GDAL_CALC(1) GDAL GDAL_CALC(1)
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6 gdal_calc - Command line raster calculator with numpy syntax.
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9 gdal_calc.py --calc=expression --outfile=out_filename [-A filename]
10 [--A_band=n] [-B...-Z filename] [other_options]
11 DESCRIPTION
13 Command line raster calculator with numpy syntax. Use any basic arith‐
15 metic supported by numpy arrays such as +, -, *, and \ along with logi‐
16 cal operators such as >. Note that all files must have the same dimen‐
17 sions (unless extent option is used), but no projection checking is
18 performed (unless projectionCheck option is used).
19 --help Show this help message and exit
21 -h The same as --help.
23 --calc=expression
25 Calculation in numpy syntax using +, -, /, *, or any numpy array
26 functions (i.e. log10()`). Multiple ``--calc options can be
27 listed to produce a multiband file (GDAL >= 3.2).
28 -A <filename>
30 Input gdal raster file, you can use any letter (a-z, A-Z).
31 (lower case supported since GDAL 3.3)
32 A letter may be repeated (GDAL >= 3.3). The effect will be to
34 create a 3-dim numpy array. In such a case, the calculation
35 formula must use this input as a 3-dim array and must return a
36 2D array (see examples below). In case the calculation does not
37 return a 2D array an error would be generated.
38 --A_band=<n>
40 Number of raster band for file A (default 1).
41 --outfile=<filename>
43 Output file to generate or fill.
44 --NoDataValue=<value>
46 Output NoDataValue (default datatype specific value). To indi‐
47 cate not setting a NoDataValue use --NoDataValue=none (GDAL >=
48 3.3)
49 NOTE:
51 Using the Python API: None value will indicate default
52 datatype specific value. 'none' value will indicate not set‐
53 ting a NoDataValue.
54 --hideNoData
56 ..versionadded:: 3.3
57 Ignores the input bands NoDataValue. By default, the input
59 bands NoDataValue are not participating in the calculation. By
60 setting this setting - no special treatment will be performed on
61 the input NoDataValue. and they will be participating in the
62 calculation as any other value. The output will not have a set
63 NoDataValue, unless you explicitly specified a specific value by
64 setting --NoDataValue=<value>.
65 --type=<datatype>
67 Output datatype, must be one of [Int32, Int16, Float64, UInt16,
68 Byte, UInt32, Float32].
69 NOTE:
71 Despite the datatype set using --type, when doing intermedi‐
72 ate aritmethic operations using operands of the same type,
73 the operation result will honor the original datatype. This
74 may lead into unexpected results in the final result.
75 --format=<gdal_format>
77 GDAL format for output file.
78 color-table=<filename>
80 Allows specifying a filename of a color table (or a ColorTable
81 object) (with Palette Index interpretation) to be used for the
82 output raster. Supported formats: txt (i.e. like gdaldem, but
83 color names are not supported), qlr, qml (i.e. exported from
84 QGIS)
85 --extent=<option>
87 ..versionadded:: 3.3
88 this option determines how to handle rasters with different ex‐
90 tents. this option is mutually exclusive with the projwin op‐
91 tion, which is used for providing a custom extent. for all the
92 options below the pixel size (resolution) and SRS (Spatial Ref‐
93 erence System) of all the input rasters must be the same. ig‐
94 nore (default) - only the dimensions of the rasters are com‐
95 pared. if the dimensions do not agree the operation will fail.
96 fail - the dimensions and the extent (bounds) of the rasters
97 must agree, otherwise the operation will fail. union - the ex‐
98 tent (bounds) of the output will be the minimal rectangle that
99 contains all the input extents. intersect - the extent (bounds)
100 of the output will be the maximal rectangle that is contained in
101 all the input extents.
102 --projwin <ulx> <uly> <lrx> <lry>
104 ..versionadded:: 3.3
105 this option provides a custom extent for the output, it is mutu‐
107 ally exclusive with the extent option.
108 --projectionCheck
110 ..versionadded:: 3.3
111 By default, no projection checking will be performed. By set‐
113 ting this option, if the projection is not the same for all
114 bands then the operation will fail.
115 --creation-option=<option>
117 Passes a creation option to the output format driver. Multiple
118 options may be listed. See format specific documentation for le‐
119 gal creation options for each format.
120 --co=<option>
122 The same as creation-option.
123 --allBands=[a-z, A-Z]
125 Process all bands of given raster (a-z, A-Z). Requires a single
126 calc for all bands.
127 --overwrite
129 Overwrite output file if it already exists.
130 --debug
132 Print debugging information.
133 --quiet
135 Suppress progress messages.
136
138 ..versionadded:: 3.3
139 The following options are available by using function the python inter‐
141 face of gdal_calc. They are not available using the command prompt.
142 user_namespace
144 A dictionary of custom functions or other names to be available
145 for use in the Calc expression.
146 return_ds
148 If enabled, the output dataset would be returned from the func‐
149 tion and not closed.
150 color_table
152 Allows specifying a ColorTable object (with Palette Index inter‐
153 pretation) to be used for the output raster.
154
156 Add two files together:
157 gdal_calc.py -A input1.tif -B input2.tif --outfile=result.tif --calc="A+B"
159 Average of two layers:
161 gdal_calc.py -A input1.tif -B input2.tif --outfile=result.tif --calc="(A+B)/2"
163 NOTE:
165 In the previous example, beware that if A and B inputs are of the
166 same datatype, for example integers, you may need to force the con‐
167 version of one of the operands before the division operation.
168 gdal_calc.py -A input.tif -B input2.tif --outfile=result.tif --calc="(A.astype(numpy.float64) + B) / 2"
170 Add three files together (two options with the same result):
172 gdal_calc.py -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="A+B+C"
174 ..versionadded:: 3.3
176 gdal_calc.py -A input1.tif -A input2.tif -A input3.tif --outfile=result.tif --calc="numpy.sum(A,axis=0)".
178 Average of three layers (two options with the same result):
180 gdal_calc.py -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="(A+B+C)/3"
182 ..versionadded:: 3.3
184 gdal_calc.py -A input1.tif -A input2.tif -A input3.tif --outfile=result.tif --calc="numpy.average(a,axis=0)".
186 Maximum of three layers (two options with the same result):
188 gdal_calc.py -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="numpy.max((A,B,C),axis=0)"
190 ..versionadded:: 3.3
192 gdal_calc.py -A input1.tif -A input2.tif -A input3.tif --outfile=result.tif --calc="numpy.max(A,axis=0)"
194 Set values of zero and below to null:
196 gdal_calc.py -A input.tif --outfile=result.tif --calc="A*(A>0)" --NoDataValue=0
198 Using logical operator to keep a range of values from input:
200 gdal_calc.py -A input.tif --outfile=result.tif --calc="A*logical_and(A>100,A<150)"
202 Work with multiple bands:
204 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)"
206
208 Chris Yesson <chris dot yesson at ioz dot ac dot uk>, Etienne Tourigny
209 <etourigny dot dev at gmail dot com>
210
212 1998-2021
213 Sep 07, 2021 GDAL_CALC(1)