cv2.CacadeClassifier error fix attempt

inference_utils.py

@@ -8,6 +8,7 @@ import numpy as np
 import torch
 from PIL import Image
 from torchvision import transforms
+import threading
 
 # Shim for spaces to allow local execution without the package
 try:
@@ -69,7 +70,17 @@ class FaceEyeExtractor:
         self._yolo_model = None
         self._yolo_device = None
         self._stride = 32
-        self._cascade = None
+        self._tl = threading.local()
+
+    def __getstate__(self):
+        state = self.__dict__.copy()
+        if "_tl" in state:
+            del state["_tl"]
+        return state
+
+    def __setstate__(self, state):
+        self.__dict__.update(state)
+        self._tl = threading.local()
 
     def _patch_torch_load_for_old_ckpt(self):
         import torch as _torch
@@ -151,9 +162,10 @@ class FaceEyeExtractor:
         if not self.cascade_path.exists():
             raise RuntimeError(f"Cascade xml not found: {self.cascade_path}")
             
-        self._cascade = cv2.CascadeClassifier(str(self.cascade_path))
-        if self._cascade.empty():
+        cascade = cv2.CascadeClassifier(str(self.cascade_path))
+        if cascade.empty():
             raise RuntimeError(f"cascade load failed: {self.cascade_path}")
+        self._tl.cascade = cascade
 
     def _letterbox_compat(self, img0, new_shape, stride):
         from utils.datasets import letterbox  # type: ignore
@@ -255,7 +267,14 @@ class FaceEyeExtractor:
         dyn_min = int(0.07 * min_side)
         min_sz = max(8, int(self.eye_min_size), dyn_min)
 
-        raw = self._cascade.detectMultiScale(
+        cascade = getattr(self._tl, 'cascade', None)
+        if cascade is None:
+            cascade = cv2.CascadeClassifier(str(self.cascade_path))
+            if cascade.empty():
+                raise RuntimeError(f"cascade load failed: {self.cascade_path}")
+            self._tl.cascade = cascade
+
+        raw = cascade.detectMultiScale(
             proc,
             scaleFactor=1.15,
             minNeighbors=self.neighbors,