code: def pad(image, desired_size=(513, 513), value=None):
      # mean pixel value
      if value == None:
          value = 127.5
      old_size = image.shape[
          :2
      ]  # old_size is in (height, width) format
  
      new_size = tuple(
          [x + max(ds - x, 0) for x, ds in zip(old_size, desired_size)]
      )
  
      # Pad image with mean pixel value
      new_im = np.pad(
          image,
          (
              (0, (new_size[0] - old_size[0])),
              (0, new_size[1] - old_size[1]),
              (0, 0),
          ),
          mode="constant",
          constant_values=value,
      )
      return new_im
  
imports: import numpy
  from nnabla.utils.image_utils import imresize
label_desc: Use image node_id 4 for calling a global function with example usage: pad(image, desired_size, value) and returns: new_im