Fix cutline handling for cases with multiple resolutions

rio_tiler/models.py

@@ -422,23 +422,28 @@ def create_from_list(cls, data: Sequence["ImageData"]) -> "ImageData":
 
         """
         h, w = zip(*[(img.height, img.width) for img in data])
+
+        # Get cutline mask at highest resolution.
+        max_h, max_w = max(h), max(w)
+        cutline_mask = next(
+            img.cutline_mask
+            for img in data
+            if img.height == max_h and img.width == max_w
+        )
+
         if len(set(h)) > 1 or len(set(w)) > 1:
             warnings.warn(
                 "Cannot concatenate images with different size. Will resize using max width/heigh",
                 UserWarning,
             )
-            max_h, max_w = max(h), max(w)
             for img in data:
                 if img.height == max_h and img.width == max_w:
-                    cutline_mask = img.cutline_mask
                     continue
                 arr = numpy.ma.MaskedArray(
                     resize_array(img.array.data, max_h, max_w),
-                    mask=resize_array(img.array.mask * 1, max_h, max_w).astype("bool"),
+                    mask=cutline_mask,
                 )
                 img.array = arr
-        else:
-            cutline_mask = data[0].cutline_mask
 
         arr = numpy.ma.concatenate([img.array for img in data])