code: def _adjust_contrast_torchvision_uint8(img, factor, mean):
      lut = np.arange(0, 256) * factor
      lut = lut + mean * (1 - factor)
      lut = clip(lut, img.dtype, 255)
  
      return cv2.LUT(img, lut)
  
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 51 for calling a global function with example usage: _adjust_contrast_torchvision_uint8(img, factor, mean) and returns: cv2