Use format as a falback

mb-util

@@ -48,7 +48,7 @@ if __name__ == '__main__':
     parser.add_option('--image_format', dest='format',
         help='''The format of the image tiles, either png, jpg, webp or pbf''',
         choices=['png', 'jpg', 'pbf', 'webp'],
-        default='png')
+        default=None)
 
     parser.add_option('--grid_callback', dest='callback',
         help='''Option to control JSONP callback for UTFGrid tiles. If grids are not '''

mbutil/util.py

@@ -221,7 +221,7 @@ def disk_to_mbtiles(directory_path, mbtiles_file, **kwargs):
     optimize_connection(cur)
     mbtiles_setup(cur, use_deduplication=use_compression)
 
-    image_format = kwargs.get('format', 'png')
+    image_format = kwargs.get('format') or 'png'
 
     # Load metadata
     try:
@@ -517,9 +517,9 @@ def mbtiles_to_disk(mbtiles_file, directory_path, **kwargs):
             os.makedirs(tile_dir)
 
         if kwargs.get('scheme') == 'wms':
-            tile = os.path.join(tile_dir, '%03d.%s' % (int(y) % 1000, kwargs.get('format', 'png')))
+            tile = os.path.join(tile_dir, '%03d.%s' % (int(y) % 1000, kwargs.get('format') or 'png'))
         else:
-            tile = os.path.join(tile_dir, '%s.%s' % (y, kwargs.get('format', 'png')))
+            tile = os.path.join(tile_dir, '%s.%s' % (y, kwargs.get('format') or 'png'))
 
         f = open(tile, 'wb')
         f.write(t[3])
@@ -668,7 +668,7 @@ def disk_to_pmtiles(directory_path, pmtiles_file, **kwargs):
             logger.info("Importing disk to PMTiles")
             logger.debug("%s --> %s" % (directory_path, pmtiles_file))
 
-        image_format = kwargs.get('format', 'png')
+        image_format = kwargs.get('format') or 'png'
 
         stats = {
             'total_tiles': 0,
@@ -848,7 +848,7 @@ def pmtiles_metadata_to_disk(pmtiles_file, **kwargs):
             reader = Reader(MmapSource(f))
             header = reader.header()
             metadata = reader.metadata()
-            pmtiles_header_to_metadata(header, metadata, kwargs.get('format', 'png'))
+            pmtiles_header_to_metadata(header, metadata, kwargs.get('format') or 'png')
 
         if not silent:
             logger.debug(json.dumps(metadata, indent=2))
@@ -867,10 +867,10 @@ def pmtiles_to_disk(pmtiles_file, directory_path, **kwargs):
             header = reader.header()
             metadata = reader.metadata()
 
-            file_ext = get_tile_ext(header, kwargs.get('format', 'png'))
+            file_ext = get_tile_ext(header, kwargs.get('format') or 'png')
 
             # Populate metadata with missing standard fields from the PMTiles header
-            pmtiles_header_to_metadata(header, metadata, kwargs.get('format', 'png'))
+            pmtiles_header_to_metadata(header, metadata, kwargs.get('format') or 'png')
 
             with open(os.path.join(directory_path, 'metadata.json'), 'w') as md_f:
                 json.dump(metadata, md_f, indent=4)
@@ -957,7 +957,7 @@ def mbtiles_to_pmtiles_cmd(mbtiles_file, pmtiles_file, **kwargs):
             mbtiles_metadata.pop('scheme', None)
 
             # Resolve format: user flag > metadata > default 'png'
-            image_format = kwargs.get('format', mbtiles_metadata.get('format', 'png'))
+            image_format = kwargs.get('format') or mbtiles_metadata.get('format', 'png')
             mbtiles_metadata['format'] = image_format
 
             is_pbf = image_format in ("pbf", "mvt")
@@ -1034,9 +1034,9 @@ def pmtiles_to_mbtiles_cmd(pmtiles_file, mbtiles_file, **kwargs):
             header = reader.header()
             metadata = reader.metadata()
 
-            file_ext = get_tile_ext(header, kwargs.get('format', 'png'))
+            file_ext = get_tile_ext(header, kwargs.get('format') or 'png')
 
-            pmtiles_header_to_metadata(header, metadata, kwargs.get('format', 'png'))
+            pmtiles_header_to_metadata(header, metadata, kwargs.get('format') or 'png')
 
             # MBTiles stores tiles in TMS scheme
             metadata['scheme'] = 'tms'

test/test_pmtiles.py

@@ -16,6 +16,7 @@
 
 OUTPUT_DIR = 'test/output'
 ONE_TILE_MBTILES = 'test/data/one_tile.mbtiles'
+ONE_TILE_WEBP_MBTILES = 'test/data/one_tile_webp.mbtiles'
 
 
 def _output(*parts):
@@ -207,5 +208,92 @@ def test_prepare_metadata_no_json_row_when_no_vector_layers(self):
         self.assertNotIn('json', packed)
 
 
+class WebpFormatPreservationTestCase(unittest.TestCase):
+    """Regression tests for webp format being preserved through conversions.
+
+    Previously, the --image_format CLI option defaulted to 'png', which meant
+    mbtiles_to_pmtiles_cmd always received format='png' in kwargs — overriding
+    the 'webp' value stored in the MBTiles metadata.
+    """
+
+    def setUp(self):
+        shutil.rmtree(OUTPUT_DIR, ignore_errors=True)
+        os.makedirs(OUTPUT_DIR, exist_ok=True)
+        self.webp_mbtiles = ONE_TILE_WEBP_MBTILES
+
+    def tearDown(self):
+        shutil.rmtree(OUTPUT_DIR, ignore_errors=True)
+
+    def _read_pmtiles_header_and_meta(self, path):
+        import sys
+        import os as _os
+        _pmtiles_path = _os.path.abspath(_os.path.join(
+            _os.path.dirname(__file__), '..', 'PMTiles', 'python', 'pmtiles'))
+        if _pmtiles_path not in sys.path:
+            sys.path.append(_pmtiles_path)
+        from pmtiles.reader import Reader, MmapSource
+        with open(path, 'rb') as f:
+            reader = Reader(MmapSource(f))
+            return reader.header(), reader.metadata()
+
+    def test_webp_format_preserved_in_pmtiles_header(self):
+        """mbtiles→pmtiles: tile_type in PMTiles header must reflect webp, not png."""
+        import sys
+        import os as _os
+        _pmtiles_path = _os.path.abspath(_os.path.join(
+            _os.path.dirname(__file__), '..', 'PMTiles', 'python', 'pmtiles'))
+        if _pmtiles_path not in sys.path:
+            sys.path.append(_pmtiles_path)
+        from pmtiles.tile import TileType
+
+        out = _output('webp.pmtiles')
+        # No format kwarg passed — should auto-detect 'webp' from metadata
+        mbtiles_to_pmtiles_cmd(self.webp_mbtiles, out, silent=True)
+
+        header, _ = self._read_pmtiles_header_and_meta(out)
+        self.assertEqual(header['tile_type'], TileType.WEBP,
+                         "PMTiles header tile_type should be WEBP, got %s" % header['tile_type'])
+
+    def test_webp_format_preserved_in_pmtiles_metadata(self):
+        """mbtiles→pmtiles: 'format' key in PMTiles metadata must be 'webp'."""
+        out = _output('webp.pmtiles')
+        mbtiles_to_pmtiles_cmd(self.webp_mbtiles, out, silent=True)
+
+        _, meta = self._read_pmtiles_header_and_meta(out)
+        self.assertEqual(meta.get('format'), 'webp',
+                         "PMTiles metadata format should be 'webp', got %r" % meta.get('format'))
+
+    def test_explicit_format_flag_overrides_metadata(self):
+        """Explicit --image_format=png overrides source metadata format."""
+        import sys
+        import os as _os
+        _pmtiles_path = _os.path.abspath(_os.path.join(
+            _os.path.dirname(__file__), '..', 'PMTiles', 'python', 'pmtiles'))
+        if _pmtiles_path not in sys.path:
+            sys.path.append(_pmtiles_path)
+        from pmtiles.tile import TileType
+
+        out = _output('webp_forced_png.pmtiles')
+        mbtiles_to_pmtiles_cmd(self.webp_mbtiles, out, silent=True, format='png')
+
+        header, meta = self._read_pmtiles_header_and_meta(out)
+        self.assertEqual(header['tile_type'], TileType.PNG)
+        self.assertEqual(meta.get('format'), 'png')
+
+    def test_webp_format_survives_pmtiles_to_mbtiles_roundtrip(self):
+        """webp format survives mbtiles → pmtiles → mbtiles roundtrip."""
+        pmtiles_path = _output('webp.pmtiles')
+        mbtiles_out = _output('webp_roundtrip.mbtiles')
+
+        mbtiles_to_pmtiles_cmd(self.webp_mbtiles, pmtiles_path, silent=True)
+        pmtiles_to_mbtiles_cmd(pmtiles_path, mbtiles_out, silent=True)
+
+        con = sqlite3.connect(mbtiles_out)
+        meta = dict(con.execute("SELECT name, value FROM metadata"))
+        con.close()
+        self.assertEqual(meta.get('format'), 'webp',
+                         "format should be 'webp' after roundtrip, got %r" % meta.get('format'))
+
+
 if __name__ == '__main__':
     unittest.main()