NAME

       gdalcompare -  Compare two images.

SYNOPSIS

          gdalcompare.py [--help] [--help-general]
                         [-dumpdiffs] [-skip_binary] [-skip_overviews]
                         [-skip_geolocation] [-skip_geotransform]
                         [-skip_metadata] [-skip_rpc] [-skip_srs]
                         [-sds] <golden_file> <new_file>

DESCRIPTION

       The   gdalcompare.py   script  compares  two  GDAL  supported  datasets  and  reports  the
       differences. In addition to reporting differences to the standard output the  script  will
       also return the difference count in its exit value.

       Image  pixels,  and  various metadata are checked. There is also a byte by byte comparison
       done which will count as one difference. So if it is only important that the GDAL  visible
       data  is  identical  a  difference count of 1 (the binary difference) should be considered
       acceptable.

       --help Show this help message and exit

       --help-general
              Gives a brief usage message for the generic GDAL commandline options and exit.

       -dumpdiffs
              New in version 3.8.

              Whether to output the difference in pixel content in a TIFF  file  in  the  current
              directory.

       -skip_binary
              New in version 3.8.

              Whether to skip exact comparison of binary content.

       -skip_overviews
              New in version 3.8.

              Whether to skip comparison of overviews.

       -skip_geolocation
              New in version 3.8.

              Whether to skip comparison of GEOLOCATION metadata domain.

       -skip_geotransform
              New in version 3.8.

              Whether to skip comparison of geotransform matrix.

       -skip_metadata
              New in version 3.8.

              Whether to skip comparison of metadata

       -skip_rpc
              New in version 3.8.

              Whether  to  skip  comparison  of  Rational  Polynomial Coefficients (RPC) metadata
              domain.

       -skip_srs
              New in version 3.8.

              Whether to skip comparison of spatial reference systems (SRS).

       -sds   If this flag is passed the script will compare all subdatasets that are part of the
              dataset, otherwise subdatasets are ignored.

       <golden_file>
              The file that is considered correct, referred to as the golden file.

       <new_file>
              The file being compared to the golden file, referred to as the new file.

       Note  that  the gdalcompare.py script (like all the other scripts) can also be called as a
       library from python code: from osgeo_utils import gdalcompare.  The primary entry point is
       gdalcompare.compare_db()  which  takes  a  golden  gdal.Dataset  and a new gdal.Dataset as
       arguments  and  returns  a  difference  count  (excluding  the  binary  comparison).   The
       gdalcompare.compare_sds() entry point can be used to compare subdatasets.

EXAMPLES

          gdalcompare.py -dumpdiffs N.tiff S.tiff; echo $?
          Files differ at the binary level.
          Band 1 checksum difference:
            Golden: 36694
            New:    40645
            Pixels Differing: 1509
            Maximum Pixel Difference: 255.0
            Wrote Diffs to: 1.tif
          Differences Found: 2
          2

          gdalcompare.py N.tiff N.tiff; echo $?
          Differences Found: 0
          0

AUTHOR

       Frank Warmerdam <warmerdam@pobox.com>

COPYRIGHT

       1998-2024

                                           Oct 07, 2024                            GDALCOMPARE(1)