code: def brightness(batch: List[np.ndarray]) -> List[float]:
      """Calculate brightness on each image in the batch."""
      return [
          img.mean() if _is_grayscale(img) else rgb2gray(img).mean()
          for img in batch
      ]
  
imports: from typing import Dict, List, Tuple
  import numpy
  from cv2 import CV_64F, Laplacian
  from skimage.color import rgb2gray
label_desc: Use image node_id 3 for calling a global function with example usage: brightness(batch) and returns: unknown