gdalenhance: add minimal tests

Co-authored-by: Even Rouault <[email protected]>

autotest/pymod/test_cli_utilities.py

@@ -208,6 +208,14 @@ def get_gdaldem_path():
 #
 
 
+def get_gdalenhance_path():
+    return get_cli_utility_path("gdalenhance")
+
+
+###############################################################################
+#
+
+
 def get_gdal_rasterize_path():
     return get_cli_utility_path("gdal_rasterize")
 

autotest/utilities/test_gdalenhance.py

@@ -0,0 +1,90 @@
+#!/usr/bin/env pytest
+# -*- coding: utf-8 -*-
+###############################################################################
+#
+# Project:  GDAL/OGR Test Suite
+# Purpose:  gdalenhance testing
+# Author:   Daniel Baston <dbaston at gmail.com>
+#
+###############################################################################
+# Copyright (c) 2024, ISciences LLC
+#
+# SPDX-License-Identifier: MIT
+###############################################################################
+
+import gdaltest
+import pytest
+import test_cli_utilities
+
+from osgeo import gdal
+
+pytestmark = pytest.mark.skipif(
+    test_cli_utilities.get_gdalenhance_path() is None,
+    reason="gdalenhance not available",
+)
+
+
+@pytest.fixture()
+def gdalenhance_path():
+    return test_cli_utilities.get_gdalenhance_path()
+
+
+###############################################################################
+# Output a lookup table, then apply it to the image
+
+
+def test_gdalenhance_output_histogram(gdalenhance_path, tmp_path):
+
+    out, err = gdaltest.runexternal_out_and_err(
+        f"{gdalenhance_path} -equalize ../gcore/data/rgbsmall.tif"
+    )
+
+    assert not err
+
+    lines = out.strip().split("\n")
+    assert len(lines) == 3
+
+    assert lines[0].startswith("1:Band ")
+    assert lines[1].startswith("2:Band ")
+    assert lines[2].startswith("3:Band ")
+
+    lut_fname = tmp_path / "lut.txt"
+
+    with open(lut_fname, "w") as outfile:
+        for line in lines:
+            outfile.write(line.strip())
+            outfile.write("\n")
+
+    enhanced_fname = tmp_path / "out.tif"
+
+    out, err = gdaltest.runexternal_out_and_err(
+        f"{gdalenhance_path} -config {lut_fname} ../gcore/data/rgbsmall.tif {enhanced_fname}"
+    )
+
+    assert not err
+
+    assert enhanced_fname.exists()
+
+
+###############################################################################
+# Write a new image directly
+
+
+def test_gdalenhance_output_image(gdalenhance_path, tmp_path):
+
+    infile = "../gcore/data/rgbsmall.tif"
+    outfile = tmp_path / "out.tif"
+
+    out, err = gdaltest.runexternal_out_and_err(
+        f"{gdalenhance_path} -quiet -equalize -co COMPRESS=DEFLATE {infile} {outfile}"
+    )
+
+    assert not err
+
+    with gdal.Open(infile) as src, gdal.Open(outfile) as dst:
+        assert src.RasterCount == dst.RasterCount
+        assert src.RasterXSize == dst.RasterXSize
+        assert src.RasterYSize == dst.RasterYSize
+
+        # check that -co was honored
+        assert dst.GetMetadata("IMAGE_STRUCTURE")["COMPRESSION"] == "DEFLATE"