Handle colormaps instances

localtileserver/client.py

@@ -4,7 +4,7 @@
 import pathlib
 from typing import List, Optional, Union
 
-from matplotlib.colors import Colormap
+from matplotlib.colors import Colormap, ListedColormap
 import rasterio
 import requests
 from rio_tiler.io import Reader
@@ -448,7 +448,9 @@ def get_tile_url(
         if indexes is not None:
             params["indexes"] = indexes
         if colormap is not None:
-            if isinstance(colormap, Colormap):
+            if isinstance(colormap, ListedColormap):
+                colormap = json.dumps([c for c in colormap.colors])
+            elif isinstance(colormap, Colormap):
                 colormap = json.dumps(
                     {k: tuple(v.tolist()) for k, v in enumerate(colormap(range(256), 1, 1))}
                 )

localtileserver/tiler/handler.py

@@ -1,7 +1,9 @@
 """Methods for working with images."""
+import json
 import pathlib
 from typing import Dict, List, Optional, Tuple, Union
 
+from matplotlib.colors import Colormap, LinearSegmentedColormap, ListedColormap
 import numpy as np
 import rasterio
 from rasterio.enums import ColorInterp
@@ -150,13 +152,14 @@ def _render_image(
     colormap: Optional[str] = None,
     img_format: str = "PNG",
 ):
-    import json
-
-    from matplotlib.colors import LinearSegmentedColormap
-
     if colormap in cmap.list():
         colormap = cmap.get(colormap)
-    elif colormap:
+    elif isinstance(colormap, ListedColormap):
+        c = LinearSegmentedColormap.from_list("", colormap.colors, N=256)
+        colormap = {k: tuple(v) for k, v in enumerate(c(range(256), 1, 1))}
+    elif isinstance(colormap, Colormap):
+        colormap = {k: tuple(v) for k, v in enumerate(colormap(range(256), 1, 1))}
+    else:
         c = json.loads(colormap)
         if isinstance(c, list):
             c = LinearSegmentedColormap.from_list("", c, N=256)