gdalwarp - Image reprojection and warping utility.
gdalwarp [--help-general] [--formats]
[-s_srs srs_def] [-t_srs srs_def] [-ct string] [-to "NAME=VALUE"]* [-novshiftgrid]
[-order n | -tps | -rpc | -geoloc] [-et err_threshold]
[-refine_gcps tolerance [minimum_gcps]]
[-te xmin ymin xmax ymax] [-te_srs srs_def]
[-tr xres yres] [-tap] [-ts width height]
[-ovr level|AUTO|AUTO-n|NONE] [-wo "NAME=VALUE"] [-ot Byte/Int16/...] [-wt Byte/Int16]
[-srcnodata "value [value...]"] [-dstnodata "value [value...]"]
[-srcalpha|-nosrcalpha] [-dstalpha]
[-r resampling_method] [-wm memory_in_mb] [-multi] [-q]
[-cutline datasource] [-cl layer] [-cwhere expression]
[-csql statement] [-cblend dist_in_pixels] [-crop_to_cutline]
[-if format]* [-of format] [-co "NAME=VALUE"]* [-overwrite]
[-nomd] [-cvmd meta_conflict_value] [-setci] [-oo NAME=VALUE]*
[-doo NAME=VALUE]*
srcfile* dstfile
The gdalwarp utility is an image mosaicing, reprojection
and warping utility. The program can reproject to any supported projection,
and can also apply GCPs stored with the image if the image is
"raw" with control information.
- -s_srs <srs
def>
- Set source spatial reference.
The coordinate systems that can be passed are anything
supported by the OGRSpatialReference.SetFromUserInput() call, which
includes EPSG PCS and GCSes (i.e. EPSG:4296), PROJ.4 declarations (as
above), or the name of a .prj file containing well known text. Starting
with GDAL 2.2, if the SRS has an explicit vertical datum that points to
a PROJ.4 geoidgrids, and the input dataset is a single band dataset, a
vertical correction will be applied to the values of the dataset.
- -t_srs
<srs_def>
- Set target spatial reference.
The coordinate systems that can be passed are anything
supported by the OGRSpatialReference.SetFromUserInput() call, which
includes EPSG PCS and GCSes (i.e. EPSG:4296), PROJ.4 declarations (as
above), or the name of a .prj file containing well known text. Starting
with GDAL 2.2, if the SRS has an explicit vertical datum that points to
a PROJ.4 geoidgrids, and the input dataset is a single band dataset, a
vertical correction will be applied to the values of the dataset.
- -ct <string>
- A PROJ string (single step operation or multiple step string starting with
+proj=pipeline), a WKT2 string describing a CoordinateOperation, or a
urn:ogc:def:coordinateOperation:EPSG::XXXX URN overriding the
default transformation from the source to the target CRS. It must take
into account the axis order of the source and target CRS.
New in version 3.0.
- -to
<NAME=VALUE>
- Set a transformer option suitable to pass to
GDALCreateGenImgProjTransformer2().
- -novshiftgrid
- Disable the use of vertical datum shift grids when one of the source or
target SRS has an explicit vertical datum, and the input dataset is a
single band dataset.
New in version 2.2.
- -order
<n>
- order of polynomial used for warping (1 to 3). The default is to select a
polynomial order based on the number of GCPs.
- -tps
- Force use of thin plate spline transformer based on available GCPs.
- -geoloc
- Force use of Geolocation Arrays.
- -et
<err_threshold>
- Error threshold for transformation approximation (in pixel units -
defaults to 0.125, unless, starting with GDAL 2.1, the RPC_DEM warping
option is specified, in which case, an exact transformer, i.e.
err_threshold=0, will be used).
- -refine_gcps
<tolerance minimum_gcps>
- Refines the GCPs by automatically eliminating outliers. Outliers will be
eliminated until minimum_gcps are left or when no outliers can be
detected. The tolerance is passed to adjust when a GCP will be eliminated.
Not that GCP refinement only works with polynomial interpolation. The
tolerance is in pixel units if no projection is available, otherwise it is
in SRS units. If minimum_gcps is not provided, the minimum GCPs according
to the polynomial model is used.
- -te <xmin ymin xmax
ymax>
- Set georeferenced extents of output file to be created (in target SRS by
default, or in the SRS specified with -te_srs)
- -te_srs
<srs_def>
- Specifies the SRS in which to interpret the coordinates given with -te.
The <srs_def> may be any of the usual GDAL/OGR forms, complete WKT,
PROJ.4, EPSG:n or a file containing the WKT. This must not be confused
with -t_srs which is the target SRS of the output dataset. -te_srs
is a convenience e.g. when knowing the output coordinates in a geodetic
long/lat SRS, but still wanting a result in a projected coordinate
system.
- -tap
- (target aligned pixels) align the coordinates of the extent of the output
file to the values of the -tr, such that the aligned extent
includes the minimum extent.
- -ts <width>
<height>
- Set output file size in pixels and lines. If width or height is set to 0,
the other dimension will be guessed from the computed resolution. Note
that -ts cannot be used with -tr
- -ovr
<level|AUTO|AUTO-n|NONE>
- To specify which overview level of source files must be used. The default
choice, AUTO, will select the overview level whose resolution is the
closest to the target resolution. Specify an integer value (0-based, i.e.
0=1st overview level) to select a particular level. Specify AUTO-n where n
is an integer greater or equal to 1, to select an overview level below the
AUTO one. Or specify NONE to force the base resolution to be used (can be
useful if overviews have been generated with a low quality resampling
method, and the warping is done using a higher quality resampling
method).
- -wo
`"NAME=VALUE"`
- Set a warp option. The GDALWarpOptions::papszWarpOptions docs show
all options. Multiple -wo options may be listed.
- -ot <type>
- Force the output image bands to have a specific data type supported by the
driver, which may be one of the following: Byte, UInt16,
Int16, UInt32, Int32, Float32, Float64,
CInt16, CInt32, CFloat32 or CFloat64.
- -wt <type>
- Working pixel data type. The data type of pixels in the source image and
destination image buffers.
- -r
<resampling_method>
- Resampling method to use. Available methods are:
near: nearest neighbour resampling (default, fastest
algorithm, worst interpolation quality).
bilinear: bilinear resampling.
cubic: cubic resampling.
cubicspline: cubic spline resampling.
lanczos: Lanczos windowed sinc resampling.
average: average resampling, computes the weighted
average of all non-NODATA contributing pixels.
mode: mode resampling, selects the value which appears
most often of all the sampled points.
max: maximum resampling, selects the maximum value from
all non-NODATA contributing pixels.
min: minimum resampling, selects the minimum value from
all non-NODATA contributing pixels.
med: median resampling, selects the median value of all
non-NODATA contributing pixels.
q1: first quartile resampling, selects the first
quartile value of all non-NODATA contributing pixels.
q3: third quartile resampling, selects the third
quartile value of all non-NODATA contributing pixels.
sum: compute the weighted sum of all non-NODATA
contributing pixels (since GDAL 3.1)
- -srcnodata
<value [value...]>
- Set nodata masking values for input bands (different values can be
supplied for each band). If more than one value is supplied all values
should be quoted to keep them together as a single operating system
argument. Masked values will not be used in interpolation. Use a value of
None to ignore intrinsic nodata settings on the source
dataset.
- -dstnodata
<value [value...]>
- Set nodata values for output bands (different values can be supplied for
each band). If more than one value is supplied all values should be quoted
to keep them together as a single operating system argument. New files
will be initialized to this value and if possible the nodata value will be
recorded in the output file. Use a value of None to ensure that
nodata is not defined. If this argument is not used then nodata values
will be copied from the source dataset.
- -srcalpha
- Force the last band of a source image to be considered as a source alpha
band.
- -nosrcalpha
- Prevent the alpha band of a source image to be considered as such (it will
be warped as a regular band)
New in version 2.2.
- -dstalpha
- Create an output alpha band to identify nodata (unset/transparent)
pixels.
- -wm
<memory_in_mb>
- Set the amount of memory that the warp API is allowed to use for caching.
The value is interpreted as being in megabytes if the value is less than
10000. For values >=10000, this is interpreted as bytes.
- -multi
- Use multithreaded warping implementation. Two threads will be used to
process chunks of image and perform input/output operation simultaneously.
Note that computation is not multithreaded itself. To do that, you can use
the -wo NUM_THREADS=val/ALL_CPUS option, which can be combined with
-multi
- -if <format>
- Format/driver name to be attempted to open the input file(s). It is
generally not necessary to specify it, but it can be used to skip
automatic driver detection, when it fails to select the appropriate
driver. This option can be repeated several times to specify several
candidate drivers.
New in version 3.2.
- -of <format>
- Select the output format. Starting with GDAL 2.3, if not specified, the
format is guessed from the extension (previously was GTiff). Use the short
format name.
- -co
<NAME=VALUE>
- Many formats have one or more optional creation options that can be used
to control particulars about the file created. For instance, the GeoTIFF
driver supports creation options to control compression, and whether the
file should be tiled.
The creation options available vary by format driver, and some
simple formats have no creation options at all. A list of options
supported for a format can be listed with the --formats command line
option but the documentation for the format is the definitive source of
information on driver creation options. See raster_drivers format
specific documentation for legal creation options for each format.
- -csql
<query>
- Select cutline features using an SQL query instead of from a layer with
-cl.
- -crop_to_cutline
- Crop the extent of the target dataset to the extent of the cutline.
- -overwrite
- Overwrite the target dataset if it already exists.
- -nomd
- Do not copy metadata. Without this option, dataset and band metadata (as
well as some band information) will be copied from the first source
dataset. Items that differ between source datasets will be set to * (see
-cvmd option).
- -cvmd
<meta_conflict_value>
- Value to set metadata items that conflict between source datasets (default
is "*"). Use "" to remove conflicting items.
- -setci
- Set the color interpretation of the bands of the target dataset from the
source dataset.
- <srcfile>
- The source file name(s).
- <dstfile>
- The destination file name.
Mosaicing into an existing output file is supported if the output
file already exists. The spatial extent of the existing file will not be
modified to accommodate new data, so you may have to remove it in that case,
or use the -overwrite option.
Polygon cutlines may be used as a mask to restrict the area of the
destination file that may be updated, including blending. If the OGR layer
containing the cutline features has no explicit SRS, the cutline features
must be in the SRS of the destination file. When writing to a not yet
existing target dataset, its extent will be the one of the original raster
unless -te or -crop_to_cutline are specified.
When doing vertical shift adjustments, the transformer option -to
ERROR_ON_MISSING_VERT_SHIFT=YES can be used to error out as soon as a
vertical shift value is missing (instead of 0 being used).
Starting with GDAL 3.1, it is possible to use as output format a
driver that only supports the CreateCopy operation. This may internally
imply creation of a temporary file.
gdalwarp -t_srs EPSG:4326 input.tif output.tif
- •
- For instance, an eight bit spot scene stored in GeoTIFF with control
points mapping the corners to lat/long could be warped to a UTM projection
with a command like this:
gdalwarp -t_srs '+proj=utm +zone=11 +datum=WGS84' -overwrite raw_spot.tif utm11.tif
- •
- For instance, the second channel of an ASTER image stored in HDF with
control points mapping the corners to lat/long could be warped to a UTM
projection with a command like this:
gdalwarp -overwrite HDF4_SDS:ASTER_L1B:"pg-PR1B0000-2002031402_100_001":2 pg-PR1B0000-2002031402_100_001_2.tif
- •
- To apply a cutline on a un-georeferenced image and clip from pixel
(220,60) to pixel (1160,690):
gdalwarp -overwrite -to SRC_METHOD=NO_GEOTRANSFORM -to DST_METHOD=NO_GEOTRANSFORM -te 220 60 1160 690 -cutline cutline.csv in.png out.tif
where cutline.csv content is like:
id,WKT
1,"POLYGON((....))"
- •
- To transform a DEM from geoid elevations (using EGM96) to WGS84
ellipsoidal heights:
gdalwarp -overwrite in_dem.tif out_dem.tif -s_srs EPSG:4326+5773 -t_srs EPSG:4979
Wiki page discussing options and behaviours of gdalwarp
Frank Warmerdam <warmerdam@pobox.com>, Silke Reimer
<silke@intevation.de>