code: def closest_distance(item_a, time_a, item_b, time_b, max_value):
      
      return np.minimum(item_a.closest_distance(time_a, item_b, time_b), max_value) / float(max_value)
docs: Euclidean distance between the pixels in item_a and item_b closest to each other.
  
      Args:
          item_a: STObject from the first set in ObjectMatcher
          time_a: Time integer being evaluated
          item_b: STObject from the second set in ObjectMatcher
          time_b: Time integer being evaluated
          max_value: Maximum distance value used as scaling value and upper constraint.
  
      Returns:
          Distance value between 0 and 1.