code: def filename_to_json(filename: str):
      """Turns an image filename into the respective json filename."""
      root, _ = os.path.splitext(filename)
      return f"{root}.json"
  
imports: import json
  import os
  import numpy
label_desc: Use image node_id 2 for calling a global function with example usage: filename_to_json(filename) and returns: root, str