code: def sample_norm(image: np.ndarray) -> np.ndarray:
      stretches = []
      if len(image.shape) == 3:
          for b in range(image.shape[-1]):
              stretched = exposure.equalize_hist(image[:, :, b])
              stretched /= float(np.max(stretched))
              stretches.append(stretched)
          stretched_img = np.stack(stretches, axis=2)
      else:  # if len(image.shape) == 2
          stretched_img = exposure.equalize_hist(image)
      return np.uint8(stretched_img * 255)
  
imports: import numpy
  import cv2
  from skimage import exposure
label_desc: Use image node_id 2 for calling a global function with example usage: sample_norm(image) and returns: np