rgb2pct.py: add --creation-option (OSGeo#12032)

Fixes OSGeo#12031

Author: howff

autotest/pyscripts/test_pct.py

@@ -202,6 +202,26 @@ def test_rgb2pct_2(script_path, rgb2pct2_tif):
     ds = None
 
 
+###############################################################################
+# Test rgb2pct --creation-option option
+
+
+def test_rgb2pct_creation_option(script_path, tmp_path):
+
+    tif_fname = str(tmp_path / "test_rgb2pct_creation_option.tif")
+
+    test_py_scripts.run_py_script(
+        script_path,
+        "rgb2pct",
+        "--creation-option COMPRESS=LZW "
+        + test_py_scripts.get_data_path("gcore")
+        + f"rgbsmall.tif {tif_fname}",
+    )
+
+    ds = gdal.Open(tif_fname)
+    assert ds.GetMetadataItem("COMPRESSION", "IMAGE_STRUCTURE") == "LZW"
+
+
 ###############################################################################
 # Test rgb2pct -pct option
 

doc/source/programs/rgb2pct.rst

@@ -15,7 +15,7 @@ Synopsis
 
 .. code-block::
 
-    rgb2pct [--help] [--help-general]
+    rgb2pct [--help] [--help-general] [--creation-option OPTION]
                [-n colors | -pct palette_file] [-of format] <source_file> <dest_file>
 
 Description
@@ -40,6 +40,11 @@ maximize output image visual quality.
     Select the number of colors in the generated
     color table.  Defaults to 256.  Must be between 2 and 256.
 
+.. option:: --creation-option OPTION
+
+    Optional creation parameters for the GeoTIFF driver,
+    for example "COMPRESS=LZW". Can be specified multiple times.
+
 .. option:: -pct <palette_file>
 
     Extract the color table from <palette_file> instead of computing it.

swig/python/gdal-utils/osgeo_utils/rgb2pct.py

@@ -36,6 +36,7 @@ def rgb2pct(
     dst_filename: Optional[PathLikeOrStr] = None,
     color_count: int = 256,
     driver_name: Optional[str] = None,
+    creation_options: Optional[list] = None,
 ):
     # Open source file
     src_ds = open_ds(src_filename)
@@ -81,8 +82,18 @@ def rgb2pct(
 
     gtiff_driver = gdal.GetDriverByName("GTiff")
 
+    # Convert options to list
+    if isinstance(creation_options, str):
+        creation_options = creation_options.split()
+    if not creation_options:
+        creation_options = []
+
     tif_ds = gtiff_driver.Create(
-        tif_filename, src_ds.RasterXSize, src_ds.RasterYSize, 1
+        tif_filename,
+        src_ds.RasterXSize,
+        src_ds.RasterYSize,
+        1,
+        options=creation_options,
     )
 
     tif_ds.GetRasterBand(1).SetRasterColorTable(ct)
@@ -175,6 +186,15 @@ def get_parser(self, argv) -> GDALArgumentParser:
             "palette or a color file in a supported format (txt, qml, qlr).",
         )
 
+        parser.add_argument(
+            "--creation-option",
+            "--co",
+            dest="creation_options",
+            default=[],
+            action="append",
+            help="GeoTIFF creation options, e.g. COMPRESS=LZW",
+        )
+
         parser.add_argument("src_filename", type=str, help="The input RGB file.")
 
         parser.add_argument(