add the lost 'get_image_id' function

dataset.py

@@ -407,6 +407,15 @@ def _get_val_item(self, index):
         return img, target
 
 
+def get_image_id(filename:str) -> int:
+    """Convert a string to a integer."""
+    raise NotImplementedError("Create your own 'get_image_id' function")
+    lv, no = os.path.splitext(os.path.basename(filename))[0].split("_")
+    lv = lv.replace("level", "")
+    no = f"{int(no):04d}"
+    return int(lv+no)
+
+
 if __name__ == "__main__":
     from cfg import Cfg