code: def pil_save(self, filename, fformat=None, fill_value=None,
                   compute=True, **format_kwargs):
          
          fformat = fformat or os.path.splitext(filename)[1][1:4]
          fformat = check_image_format(fformat)
  
          if fformat == 'png':
              # Take care of GeoImage.tags (if any).
              format_kwargs['pnginfo'] = self._pngmeta()
  
          img = self.pil_image(fill_value, compute=False)
          delay = img.save(filename, fformat, **format_kwargs)
          if compute:
              return delay.compute()
          return delay
docs: Save the image to the given *filename* using PIL.
  
          For now, the compression level [0-9] is ignored, due to PIL's lack of
          support. See also :meth:`save`.