1GDALADDO(1) GDAL GDALADDO(1)
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6 gdaladdo - Builds or rebuilds overview images.
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9 gdaladdo [-r {nearest,average,rms,bilinear,gauss,cubic,cubicspline,lanczos,average_magphase,mode}]
10 [-b band]* [-minsize val]
11 [-ro] [-clean] [-oo NAME=VALUE]* [--help-general] filename [levels]
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14 The gdaladdo utility can be used to build or rebuild overview images
15 for most supported file formats with one of several downsampling algo‐
16 rithms.
17 -r {nearest (default),average,rms,gauss,cubic,cubicspline,lanczos,aver‐
19 age_magphase,mode}
20 Select a resampling algorithm.
21 nearest applies a nearest neighbour (simple sampling) resampler
23 average computes the average of all non-NODATA contributing pix‐
25 els. Starting with GDAL 3.1, this is a weighted average taking
26 into account properly the weight of source pixels not contribut‐
27 ing fully to the target pixel.
28 rms computes the root mean squared / quadratic mean of all
30 non-NODATA contributing pixels (GDAL >= 3.3)
31 bilinear applies a bilinear convolution kernel.
33 gauss applies a Gaussian kernel before computing the overview,
35 which can lead to better results than simple averaging in e.g
36 case of sharp edges with high contrast or noisy patterns. The
37 advised level values should be 2, 4, 8, ... so that a 3x3 re‐
38 sampling Gaussian kernel is selected.
39 cubic applies a cubic convolution kernel.
41 cubicspline applies a B-Spline convolution kernel.
43 lanczos applies a Lanczos windowed sinc convolution kernel.
45 average_magphase averages complex data in mag/phase space.
47 mode selects the value which appears most often of all the sam‐
49 pled points.
50 -b <band>
52 Select an input band band for overview generation. Band number‐
53 ing starts from 1. Multiple -b switches may be used to select a
54 set of input bands to generate overviews.
55 -ro open the dataset in read-only mode, in order to generate exter‐
57 nal overview (for GeoTIFF especially).
58 -clean remove all overviews.
60 -oo NAME=VALUE
62 Dataset open option (format specific)
63 -minsize <val>
65 Maximum width or height of the smallest overview level. Only
66 taken into account if explicit levels are not specified. De‐
67 faults to 256.
68 New in version 2.3.
70 <filename>
73 The file to build overviews for (or whose overviews must be re‐
74 moved).
75 <levels>
77 A list of integral overview levels to build. Ignored with -clean
78 option.
79 New in version 2.3: levels are no longer required to build over‐
81 views. In which case, appropriate overview power-of-two factors
82 will be selected until the smallest overview is smaller than the
83 value of the -minsize switch.
84 gdaladdo will honour properly NODATA_VALUES tuples (special dataset
87 metadata) so that only a given RGB triplet (in case of a RGB image)
88 will be considered as the nodata value and not each value of the trip‐
89 let independently per band.
90 Selecting a level value like 2 causes an overview level that is 1/2 the
92 resolution (in each dimension) of the base layer to be computed. If
93 the file has existing overview levels at a level selected, those levels
94 will be recomputed and rewritten in place.
95 For internal GeoTIFF overviews (or external overviews in GeoTIFF for‐
97 mat), note that -clean does not shrink the file. A later run of gdal‐
98 addo with overview levels will cause the file to be expanded, rather
99 than reusing the space of the previously deleted overviews. If you just
100 want to change the resampling method on a file that already has over‐
101 views computed, you don't need to clean the existing overviews.
102 Some format drivers do not support overviews at all. Many format driv‐
104 ers store overviews in a secondary file with the extension .ovr that is
105 actually in TIFF format. By default, the GeoTIFF driver stores over‐
106 views internally to the file operated on (if it is writable), unless
107 the -ro flag is specified.
108 Most drivers also support an alternate overview format using Erdas
110 Imagine format. To trigger this use the USE_RRD =YES configuration op‐
111 tion. This will place the overviews in an associated .aux file suit‐
112 able for direct use with Imagine or ArcGIS as well as GDAL applica‐
113 tions. (e.g. --config USE_RRD YES)
114
116 External overviews created in TIFF format may be compressed using the
117 COMPRESS_OVERVIEW configuration option. All compression methods, sup‐
118 ported by the GeoTIFF driver, are available here. (e.g. --config COM‐
119 PRESS_OVERVIEW DEFLATE). The photometric interpretation can be set
120 with the PHOTOMETRIC_OVERVIEW =RGB/YCBCR/... configuration option, and
121 the interleaving with the INTERLEAVE_OVERVIEW =PIXEL/BAND configuration
122 option.
123 For JPEG compressed external overviews, the JPEG quality can be set
125 with --config JPEG_QUALITY_OVERVIEW value.
126 For WEBP compressed external and internal overviews, the WEBP quality
128 level can be set with --config WEBP_LEVEL_OVERVIEW value. If not set,
129 will default to 75.
130 For LZW or DEFLATE compressed external overviews, the predictor value
132 can be set with --config PREDICTOR_OVERVIEW 1|2|3.
133 To produce the smallest possible JPEG-In-TIFF overviews, you should
135 use:
136 --config COMPRESS_OVERVIEW JPEG --config PHOTOMETRIC_OVERVIEW YCBCR --config INTERLEAVE_OVERVIEW PIXEL
138 External overviews can be created in the BigTIFF format by using the
140 BIGTIFF_OVERVIEW configuration option: --config BIGTIFF_OVERVIEW
141 {IF_NEEDED|IF_SAFER|YES|NO}.
142 The default value is IF_SAFER starting with GDAL 2.3.0 (previously was
144 IF_NEEDED). The behavior of this option is exactly the same as the
145 BIGTIFF creation option documented in the GeoTIFF driver documentation.
146 • YES forces BigTIFF.
148 • NO forces classic TIFF.
150 • IF_NEEDED will only create a BigTIFF if it is clearly needed (uncom‐
152 pressed, and overviews larger than 4GB).
153 • IF_SAFER will create BigTIFF if the resulting file might exceed 4GB.
155 See the documentation of the raster.gtiff driver for further explana‐
157 tions on all those options.
158
160 --config GDAL_TIFF_OVR_BLOCKSIZE <size>
161 Example: --config GDAL_TIFF_OVR_BLOCKSIZE 256
163 Default value is 128, or starting with GDAL 3.1, if creating overviews
165 on a tiled GeoTIFF file, the tile size of the full resolution image.
166 Note: without this setting, the file can have the full resolution image
167 with a blocksize different from overviews blocksize.(e.g. full resolu‐
168 tion image at blocksize 256, overviews at blocksize 128)
169
171 New in version 3.2.
172 The GDAL_NUM_THREADS configuration option can be set to ALL_CPUS or a
175 integer value to specify the number of threads to use for overview com‐
176 putation.
177
179 Functionality of this utility can be done from C with GDALBuil‐
180 dOverviews().
181
183 Create overviews, embedded in the supplied TIFF file, with automatic
184 computation of levels (GDAL 2.3 or later)
185 gdaladdo -r average abc.tif
187 Create overviews, embedded in the supplied TIFF file:
189 gdaladdo -r average abc.tif 2 4 8 16
191 Create an external compressed GeoTIFF overview file from the ERDAS .IMG
193 file:
194 gdaladdo -ro --config COMPRESS_OVERVIEW DEFLATE erdas.img 2 4 8 16
196 Create an external JPEG-compressed GeoTIFF overview file from a 3-band
198 RGB dataset (if the dataset is a writable GeoTIFF, you also need to add
199 the -ro option to force the generation of external overview):
200 gdaladdo --config COMPRESS_OVERVIEW JPEG --config PHOTOMETRIC_OVERVIEW YCBCR
202 --config INTERLEAVE_OVERVIEW PIXEL rgb_dataset.ext 2 4 8 16
203 Create an Erdas Imagine format overviews for the indicated JPEG file:
205 gdaladdo --config USE_RRD YES airphoto.jpg 3 9 27 81
207 Create overviews for a specific subdataset, like for example one of po‐
209 tentially many raster layers in a GeoPackage (the "filename" parameter
210 must be driver prefix, filename and subdataset name, like e.g. shown by
211 gdalinfo):
212 gdaladdo GPKG:file.gpkg:layer
214
216 Frank Warmerdam <warmerdam@pobox.com>, Silke Reimer <silke@inteva‐
217 tion.de>
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220 1998-2021
221 Sep 07, 2021 GDALADDO(1)