gdal_merge - Mosaics a set of images.
gdal_merge.py [-o out_filename] [-of out_format] [-co NAME=VALUE]*
[-ps pixelsize_x pixelsize_y] [-tap] [-separate] [-q] [-v] [-pct]
[-ul_lr ulx uly lrx lry] [-init "value [value...]"]
[-n nodata_value] [-a_nodata output_nodata_value]
[-ot datatype] [-createonly] input_files
This utility will automatically mosaic a set of images. All the
images must be in the same coordinate system and have a matching number of
bands, but they may be overlapping, and at different resolutions. In areas
of overlap, the last image will be copied over earlier ones.
- -o
<out_filename>
- The name of the output file, which will be created if it does not already
exist (defaults to "out.tif").
- -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.
- -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.
- -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.
- -v
- Generate verbose output of mosaicing operations as they are done.
- -separate
- Place each input file into a separate band.
- -pct
- Grab a pseudo-color table from the first input image, and use it for the
output. Merging pseudo-colored images this way assumes that all input
files use the same color table.
- -init
<"value(s)">
- Pre-initialize the output image bands with these values. However, it is
not marked as the nodata value in the output file. If only one value is
given, the same value is used in all the bands.
- -createonly
- The output file is created (and potentially pre-initialized) but no input
image data is copied into it.
NOTE:
gdal_merge.py is a Python script, and will only work if
GDAL was built with Python support.
Create an image with the pixels in all bands initialized to
255.
% gdal_merge.py -init 255 -o out.tif in1.tif in2.tif
Create an RGB image that shows blue in pixels with no data. The
first two bands will be initialized to 0 and the third band will be
initialized to 255.
% gdal_merge.py -init "0 0 255" -o out.tif in1.tif in2.tif
Frank Warmerdam <warmerdam@pobox.com>, Silke Reimer
<silke@intevation.de>