gdalcompare.py: multiple enhancements

- Multiple enhancements upstreamed from Planet's version:
  * RPC metadata comparison (can be disabled with SKIP_RPC option)
  * GEOLOCATION metadata comparison (disabled with SKIP_GEOLOCATION)
  * Fix comparing NaN nodata values
  * Dump differences of pixel content (enabled with DUMP_DIFFS option)
  * Improve comparison of float32/float64 data by not just checking
    checksum but also statistics
  * Overview comparison can be skipped with SKIP_OVERVIEWS
  * Add sanity check when comparing pixel-interleave datasets with
    more than 10 bands since that can be slow.

- Binary comparison can be done on /vsi files now

- Command line utility: add ``-dumpdiffs``, ``-skip_binary``,
  ``-skip_overviews``, ``-skip_geolocation``, ``-skip_geotransform``,
  ``-skip_metadata``, ``-skip_rpc``, and ``-skip_srs`` options

- Add a test_gdalcompare.py script

autotest/pyscripts/test_gdalcompare.py

@@ -0,0 +1,303 @@
+#!/usr/bin/env pytest
+# -*- coding: utf-8 -*-
+###############################################################################
+# $Id$
+#
+# Project:  GDAL/OGR Test Suite
+# Purpose:  gdalcompare.py testing
+# Author:   Even Rouault <even dot rouault @ spatialys.com>
+#
+###############################################################################
+# Copyright (c) 2023, Even Rouault <even dot rouault at spatialys.com>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the "Software"),
+# to deal in the Software without restriction, including without limitation
+# the rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+# DEALINGS IN THE SOFTWARE.
+###############################################################################
+
+import shutil
+
+import pytest
+import test_py_scripts
+
+from osgeo import gdal
+from osgeo_utils import gdalcompare
+
+pytestmark = pytest.mark.skipif(
+    test_py_scripts.get_py_script("gdalcompare") is None,
+    reason="gdalcompare not available",
+)
+
+
+@pytest.fixture()
+def script_path():
+    return test_py_scripts.get_py_script("gdalcompare")
+
+
+@pytest.fixture()
+def captured_print():
+    def noop_print(*args, **kwargs):
+        pass
+
+    ori_print = gdalcompare.my_print
+    gdalcompare.my_print = noop_print
+    try:
+        yield
+    finally:
+        gdalcompare.my_print = ori_print
+
+
+@pytest.fixture()
+def source_filename(tmp_vsimem):
+    filename = str(tmp_vsimem / "src.tif")
+    gdal.FileFromMemBuffer(filename, open("../gcore/data/byte.tif", "rb").read())
+    return filename
+
+
+###############################################################################
+
+
+def test_gdalcompare_same(script_path, tmp_path):
+
+    source_filename = str(tmp_path / "src.tif")
+    shutil.copy("../gcore/data/byte.tif", source_filename)
+    ret = test_py_scripts.run_py_script(
+        script_path, "gdalcompare", f"{source_filename} {source_filename}"
+    )
+    assert "Differences Found: 0" in ret
+
+
+###############################################################################
+
+
+def test_gdalcompare_different_type(script_path, tmp_path):
+
+    source_filename = str(tmp_path / "src.tif")
+    shutil.copy("../gcore/data/byte.tif", source_filename)
+    ret = test_py_scripts.run_py_script(
+        script_path, "gdalcompare", f"{source_filename} ../gcore/data/uint16.tif"
+    )
+    assert "Differences Found: 0" not in ret
+    assert "Band 1 pixel types differ" in ret
+
+
+###############################################################################
+
+
+def test_gdalcompare_different_pixel_content(
+    tmp_vsimem, captured_print, source_filename
+):
+
+    golden_filename = source_filename
+    filename = str(tmp_vsimem / "new.tif")
+    gdal.Translate(filename, golden_filename, options="-scale 0 1 0 0")
+    assert (
+        gdalcompare.find_diff(golden_filename, filename, options=["SKIP_BINARY"]) == 1
+    )
+
+    prefix = str(tmp_vsimem / "")
+    gdalcompare.find_diff(
+        golden_filename,
+        filename,
+        options=["SKIP_BINARY", "DUMP_DIFFS", "DUMP_DIFFS_PREFIX=" + prefix],
+    )
+    ds = gdal.Open(prefix + "1.tif")
+    assert ds.GetRasterBand(1).Checksum() == 4672
+
+
+###############################################################################
+
+
+def test_gdalcompare_different_band_count(tmp_vsimem, captured_print, source_filename):
+
+    golden_filename = source_filename
+    filename = str(tmp_vsimem / "new.tif")
+    gdal.Translate(filename, golden_filename, options="-b 1 -b 1")
+    assert (
+        gdalcompare.find_diff(golden_filename, filename, options=["SKIP_BINARY"]) == 1
+    )
+    assert (
+        gdalcompare.find_diff(filename, golden_filename, options=["SKIP_BINARY"]) == 1
+    )
+
+
+###############################################################################
+
+
+def test_gdalcompare_different_dimension(tmp_vsimem, captured_print, source_filename):
+
+    golden_filename = source_filename
+    filename = str(tmp_vsimem / "new.tif")
+    gdal.Translate(filename, golden_filename, options="-srcwin 0 0 20 19")
+    assert (
+        gdalcompare.find_diff(golden_filename, filename, options=["SKIP_BINARY"]) == 1
+    )
+
+
+###############################################################################
+
+
+def test_gdalcompare_different_nodata(tmp_vsimem, captured_print, source_filename):
+
+    golden_filename = "../gcore/data/byte.tif"
+    filename = str(tmp_vsimem / "new.tif")
+    gdal.Translate(filename, golden_filename, options="-a_nodata 1")
+    # diff_count = 2 because of mask flags as well
+    assert (
+        gdalcompare.find_diff(golden_filename, filename, options=["SKIP_BINARY"]) == 2
+    )
+    assert (
+        gdalcompare.find_diff(filename, golden_filename, options=["SKIP_BINARY"]) == 2
+    )
+
+
+###############################################################################
+
+
+def test_gdalcompare_different_nodata_nan(tmp_vsimem, captured_print, source_filename):
+
+    golden_filename = str(tmp_vsimem / "golden.tif")
+    filename = str(tmp_vsimem / "new.tif")
+    gdal.Translate(
+        golden_filename, source_filename, options="-ot Float32 -a_nodata nan"
+    )
+    gdal.Translate(filename, source_filename, options="-ot Float32 -a_nodata 5")
+    assert (
+        gdalcompare.find_diff(golden_filename, golden_filename, options=["SKIP_BINARY"])
+        == 0
+    )
+    assert (
+        gdalcompare.find_diff(golden_filename, filename, options=["SKIP_BINARY"]) == 1
+    )
+    assert (
+        gdalcompare.find_diff(golden_filename, filename, options=["SKIP_BINARY"]) == 1
+    )
+
+
+###############################################################################
+
+
+def test_gdalcompare_different_srs(tmp_vsimem, captured_print, source_filename):
+
+    golden_filename = source_filename
+    filename = str(tmp_vsimem / "new.tif")
+
+    gdal.Translate(filename, golden_filename, options="-a_srs EPSG:4326")
+    assert (
+        gdalcompare.find_diff(golden_filename, filename, options=["SKIP_BINARY"]) == 1
+    )
+    assert (
+        gdalcompare.find_diff(
+            golden_filename, filename, options=["SKIP_SRS", "SKIP_BINARY"]
+        )
+        == 0
+    )
+
+    ds = gdal.Translate(filename, golden_filename)
+    ds.SetSpatialRef(None)
+    ds = None
+    assert (
+        gdalcompare.find_diff(golden_filename, filename, options=["SKIP_BINARY"]) != 0
+    )
+    assert (
+        gdalcompare.find_diff(filename, golden_filename, options=["SKIP_BINARY"]) != 0
+    )
+
+
+###############################################################################
+
+
+def test_gdalcompare_different_geotransform(
+    tmp_vsimem, captured_print, source_filename
+):
+
+    golden_filename = source_filename
+    filename = str(tmp_vsimem / "new.tif")
+    gdal.Translate(filename, golden_filename, options="-a_ullr 0 1 1 0")
+    assert (
+        gdalcompare.find_diff(golden_filename, filename, options=["SKIP_BINARY"]) == 1
+    )
+    assert (
+        gdalcompare.find_diff(
+            golden_filename, filename, options=["SKIP_GEOTRANSFORM", "SKIP_BINARY"]
+        )
+        == 0
+    )
+
+    ds = gdal.Translate(filename, golden_filename)
+    ds.SetGeoTransform([0, 0, 0, 0, 0, 0])
+    ds = None
+    assert (
+        gdalcompare.find_diff(golden_filename, filename, options=["SKIP_BINARY"]) != 0
+    )
+    assert (
+        gdalcompare.find_diff(filename, golden_filename, options=["SKIP_BINARY"]) != 0
+    )
+
+
+###############################################################################
+
+
+def test_gdalcompare_different_metadata(tmp_vsimem, captured_print, source_filename):
+
+    golden_filename = source_filename
+    filename = str(tmp_vsimem / "new.tif")
+    gdal.Translate(filename, golden_filename, options="-mo FOO=BAR")
+    assert (
+        gdalcompare.find_diff(golden_filename, filename, options=["SKIP_BINARY"]) == 1
+    )
+    assert (
+        gdalcompare.find_diff(filename, golden_filename, options=["SKIP_BINARY"]) == 2
+    )
+    assert (
+        gdalcompare.find_diff(
+            golden_filename, filename, options=["SKIP_METADATA", "SKIP_BINARY"]
+        )
+        == 0
+    )
+
+
+###############################################################################
+
+
+def test_gdalcompare_different_overview(tmp_vsimem, captured_print, source_filename):
+
+    golden_filename = str(tmp_vsimem / "golden.tif")
+    gdal.FileFromMemBuffer(golden_filename, open("../gcore/data/byte.tif", "rb").read())
+    ds = gdal.Open(golden_filename, gdal.GA_Update)
+    ds.BuildOverviews("NEAR", [2])
+    ds = None
+    assert (
+        gdalcompare.find_diff(golden_filename, golden_filename, options=["SKIP_BINARY"])
+        == 0
+    )
+
+    filename = str(tmp_vsimem / "new.tif")
+    gdal.Translate(filename, source_filename)
+    assert (
+        gdalcompare.find_diff(golden_filename, filename, options=["SKIP_BINARY"]) == 1
+    )
+    assert (
+        gdalcompare.find_diff(filename, golden_filename, options=["SKIP_BINARY"]) == 1
+    )
+
+    ds = gdal.Translate(filename, source_filename)
+    ds.BuildOverviews("AVERAGE", [2])
+    ds = None
+    assert (
+        gdalcompare.find_diff(golden_filename, filename, options=["SKIP_BINARY"]) == 1
+    )

doc/source/programs/gdalcompare.rst

@@ -15,7 +15,12 @@ Synopsis
 
 .. code-block::
 
-    gdalcompare.py [--help] [--help-general] [-sds] golden_file new_file
+    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
 -----------
@@ -34,6 +39,55 @@ count of 1 (the binary difference) should be considered acceptable.
 
 .. include:: options/help_and_help_general.rst
 
+.. option:: -dumpdiffs
+
+    .. versionadded:: 3.8
+
+    Whether to output the difference in pixel content in a TIFF file in the
+    current directory.
+
+.. option:: -skip_binary
+
+    .. versionadded:: 3.8
+
+    Whether to skip exact comparison of binary content.
+
+.. option:: -skip_overviews
+
+    .. versionadded:: 3.8
+
+    Whether to skip comparison of overviews.
+
+.. option:: -skip_geolocation
+
+    .. versionadded:: 3.8
+
+    Whether to skip comparison of GEOLOCATION metadata domain.
+
+.. option:: -skip_geotransform
+
+    .. versionadded:: 3.8
+
+    Whether to skip comparison of geotransform matrix.
+
+.. option:: -skip_metadata
+
+    .. versionadded:: 3.8
+
+    Whether to skip comparison of metadata
+
+.. option:: -skip_rpc
+
+    .. versionadded:: 3.8
+
+    Whether to skip comparison of Rational Polynomial Coefficients (RPC) metadata domain.
+
+.. option:: -skip_srs
+
+    .. versionadded:: 3.8
+
+    Whether to skip comparison of spatial reference systems (SRS).
+
 .. option:: -sds
 
     If this flag is passed the script will compare all subdatasets that