GDALCOMPARE(1) GDAL GDALCOMPARE(1)

NAME

gdalcompare - Compare two images.

SYNOPSIS

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

DESCRIPTION

gdalcompare 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.

NOTE:
gdalcompare is a Python utility, and is only available if GDAL
Python bindings are available.

--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 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 -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 N.tiff N.tiff; echo $?
Differences Found: 0
0

AUTHOR

Frank Warmerdam <warmerdam@pobox.com>

COPYRIGHT

1998-2025

January 8, 2025 GDALCOMPARE(1)