code: def _bottom_position(self, resource):
          
          image = self._get_scaled_image(resource)
  
          left = int(round(resource.size[0] // 2 - image.size[0] // 2))
          upper = int(round(resource.size[1] - image.size[1]))
  
          return image, left, upper
docs: Place watermark to bottom position
          :param resource: Image.Image
          :return: Image.Image