adding more nodes

backend/nodes/median_background.py

@@ -0,0 +1,44 @@
+"""Median background subtraction — extract and subtract background using local median."""
+
+from __future__ import annotations
+
+import numpy as np
+from scipy.ndimage import median_filter
+
+from backend.node_registry import register_node
+from backend.data_types import DataField
+
+
+@register_node(display_name="Median Background")
+class MedianBackground:
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "field": ("DATA_FIELD",),
+                "radius": ("INT", {"default": 20, "min": 2, "max": 500, "step": 1}),
+                "output": (["subtracted", "background"], {"default": "subtracted"}),
+            }
+        }
+
+    OUTPUTS = (
+        ('DATA_FIELD', 'result'),
+    )
+    FUNCTION = "process"
+
+    DESCRIPTION = (
+        "Extract background using a local median filter and subtract it. "
+        "The radius controls the filter window size — larger values capture "
+        "broader background variations. More robust than polynomial leveling "
+        "for surfaces with sparse tall features. "
+    )
+
+    def process(self, field: DataField, radius: int, output: str) -> tuple:
+        data = np.asarray(field.data, dtype=np.float64)
+        size = 2 * radius + 1
+        background = median_filter(data, size=size)
+
+        if output == "background":
+            return (field.replace(data=background),)
+        else:
+            return (field.replace(data=data - background),)