NAME

       gdal_merge - Mosaics a set of images.

SYNOPSIS

          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

DESCRIPTION

       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. Nodata/transparency values are considered on a band by band  level,  i.e.  a
       nodata/transparent pixel on one source band will not set a nodata/transparent value on all
       bands for the target pixel in the resulting raster nor will it  overwrite  a  valid  pixel
       value.

       -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,  Int8,  UInt16,  Int16,  UInt32,  Int32,
              UInt64, Int64, Float32, Float64, CInt16, CInt32, CFloat32 or CFloat64.

       -ps <pixelsize_x> <pixelsize_y>
              Pixel  size to be used for the output file.  If not specified the resolution of the
              first input file will be used.

       -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.
              Alignment means that xmin / resx, ymin / resy, xmax / resx  and  ymax  /  resy  are
              integer values.

       -ul_lr <ulx> <uly> <lrx> <lry>
              The  extents  of  the  output  file.  If not specified the aggregate extents of all
              input files will be used.

       -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.

       -n <nodata_value>
              Ignore pixels from files being merged in with this pixel value.

       -a_nodata <output_nodata_value>
              Assign a specified nodata value to output bands.

       -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.

EXAMPLE

       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

AUTHOR

       Frank Warmerdam <warmerdam@pobox.com>, Silke Reimer <silke@intevation.de>

COPYRIGHT

       1998-2023

                                           Jul 06, 2023                             GDAL_MERGE(1)