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 listed
27 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 New in version 3.3.
57 Ignores the input bands NoDataValue. By default, the input
60 bands NoDataValue are not participating in the calculation. By
61 setting this setting - no special treatment will be performed on
62 the input NoDataValue. and they will be participating in the
63 calculation as any other value. The output will not have a set
64 NoDataValue, unless you explicitly specified a specific value by
65 setting --NoDataValue=<value>.
66 --type=<datatype>
68 Output datatype, must be one of [Int32, Int16, Float64, UInt16,
69 Byte, UInt32, Float32].
70 NOTE:
72 Despite the datatype set using --type, when doing intermedi‐
73 ate aritmethic operations using operands of the same type,
74 the operation result will honor the original datatype. This
75 may lead into unexpected results in the final result.
76 --format=<gdal_format>
78 GDAL format for output file.
79 color-table=<filename>
81 Allows specifying a filename of a color table (or a ColorTable
82 object) (with Palette Index interpretation) to be used for the
83 output raster. Supported formats: txt (i.e. like gdaldem, but
84 color names are not supported), qlr, qml (i.e. exported from
85 QGIS)
86 --extent=<option>
88 New in version 3.3.
89 this option determines how to handle rasters with different ex‐
92 tents. this option is mutually exclusive with the projwin op‐
93 tion, which is used for providing a custom extent. for all the
94 options below the pixel size (resolution) and SRS (Spatial Ref‐
95 erence System) of all the input rasters must be the same. ig‐
96 nore (default) - only the dimensions of the rasters are com‐
97 pared. if the dimensions do not agree the operation will fail.
98 fail - the dimensions and the extent (bounds) of the rasters
99 must agree, otherwise the operation will fail. union - the ex‐
100 tent (bounds) of the output will be the minimal rectangle that
101 contains all the input extents. intersect - the extent (bounds)
102 of the output will be the maximal rectangle that is contained in
103 all the input extents.
104 --projwin <ulx> <uly> <lrx> <lry>
106 New in version 3.3.
107 this option provides a custom extent for the output, it is mutu‐
110 ally exclusive with the extent option.
111 --projectionCheck
113 New in version 3.3.
114 By default, no projection checking will be performed. By set‐
117 ting this option, if the projection is not the same for all
118 bands then the operation will fail.
119 --creation-option=<option>
121 Passes a creation option to the output format driver. Multiple
122 options may be listed. See format specific documentation for le‐
123 gal creation options for each format.
124 --co=<option>
126 The same as creation-option.
127 --allBands=[a-z, A-Z]
129 Process all bands of given raster (a-z, A-Z). Requires a single
130 calc for all bands.
131 --overwrite
133 Overwrite output file if it already exists. Overwriting must be
134 understood here as deleting and recreating the file from
135 scratch. Note that if this option is not specified and the out‐
136 put file already exists, it will be updated in place.
137 --debug
139 Print debugging information.
140 --quiet
142 Suppress progress messages.
143
145 New in version 3.3.
146 The following options are available by using function the python inter‐
149 face of gdal_calc. They are not available using the command prompt.
150 user_namespace
152 A dictionary of custom functions or other names to be available
153 for use in the Calc expression.
154 return_ds
156 If enabled, the output dataset would be returned from the func‐
157 tion and not closed.
158 color_table
160 Allows specifying a ColorTable object (with Palette Index inter‐
161 pretation) to be used for the output raster.
162
164 Add two files together:
165 gdal_calc.py -A input1.tif -B input2.tif --outfile=result.tif --calc="A+B"
167 Average of two layers:
169 gdal_calc.py -A input1.tif -B input2.tif --outfile=result.tif --calc="(A+B)/2"
171 NOTE:
173 In the previous example, beware that if A and B inputs are of the
174 same datatype, for example integers, you may need to force the con‐
175 version of one of the operands before the division operation.
176 gdal_calc.py -A input.tif -B input2.tif --outfile=result.tif --calc="(A.astype(numpy.float64) + B) / 2"
178 Add three files together (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"
182 New in version 3.3.
184 gdal_calc.py -A input1.tif -A input2.tif -A input3.tif --outfile=result.tif --calc="numpy.sum(A,axis=0)".
187 Average of three layers (two options with the same result):
189 gdal_calc.py -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="(A+B+C)/3"
191 New in version 3.3.
193 gdal_calc.py -A input1.tif -A input2.tif -A input3.tif --outfile=result.tif --calc="numpy.average(a,axis=0)".
196 Maximum of three layers (two options with the same result):
198 gdal_calc.py -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="numpy.max((A,B,C),axis=0)"
200 New in version 3.3.
202 gdal_calc.py -A input1.tif -A input2.tif -A input3.tif --outfile=result.tif --calc="numpy.max(A,axis=0)"
205 Set values of zero and below to null:
207 gdal_calc.py -A input.tif --outfile=result.tif --calc="A*(A>0)" --NoDataValue=0
209 Using logical operator to keep a range of values from input:
211 gdal_calc.py -A input.tif --outfile=result.tif --calc="A*logical_and(A>100,A<150)"
213 Work with multiple bands:
215 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)"
217
219 Chris Yesson <chris dot yesson at ioz dot ac dot uk>, Etienne Tourigny
220 <etourigny dot dev at gmail dot com>
221
223 1998-2022
224 May 04, 2022 GDAL_CALC(1)