code: def add_weighted(img1, alpha, img2, beta):
      return img1.astype(float) * alpha + img2.astype(float) * beta
  
imports: from __future__ import division
  from typing import Optional, Sequence, Union
  from warnings import warn
  import cv2
  import numpy
  import skimage
  from albumentations import random_utils
  from albumentations.augmentations.utils import MAX_VALUES_BY_DTYPE, _maybe_process_in_chunks, clip, clipped, ensure_contiguous, is_grayscale_image, is_rgb_image, non_rgb_warning, preserve_channel_dim, preserve_shape
label_desc: Use image node_id 57 for calling a global function with example usage: add_weighted(img1, alpha, img2, beta) and returns: unknown