code: def quokka_heatmap(size=None, extract=None):
      
      # TODO get rid of this deferred import
      from imgaug.augmentables.heatmaps import HeatmapsOnImage
  
      img = imageio.imread(QUOKKA_DEPTH_MAP_HALFRES_FP, pilmode="RGB")
      img = imresize_single_image(img, (643, 960), interpolation="cubic")
  
      if extract is not None:
          bb = _quokka_normalize_extract(extract)
          img = bb.extract_from_image(img)
      if size is None:
          size = img.shape[0:2]
  
      shape_resized = _compute_resized_shape(img.shape, size)
      img = imresize_single_image(img, shape_resized[0:2])
      img_0to1 = img[..., 0]  # depth map was saved as 3-channel RGB
      img_0to1 = img_0to1.astype(np.float32) / 255.0
      img_0to1 = 1 - img_0to1  # depth map was saved as 0 being furthest away
  
      return HeatmapsOnImage(img_0to1, shape=img_0to1.shape[0:2] + (3,))
docs: Returns a heatmap (here: depth map) for the standard example quokka image.
  
      Parameters
      ----------
      size : None or float or tuple of int, optional
          See :func:`imgaug.quokka`.
  
      extract : None or 'square' or tuple of number or imgaug.BoundingBox or imgaug.BoundingBoxesOnImage
          See :func:`imgaug.quokka`.
  
      Returns
      -------
      result : imgaug.HeatmapsOnImage
          Depth map as an heatmap object. Values close to 0.0 denote objects that are close to
          the camera. Values close to 1.0 denote objects that are furthest away (among all shown
          objects).