code: def _add_cam_on_image(
      img: np.ndarray, mask: np.ndarray
  ) -> np.ndarray:
      heatmap = cv2.applyColorMap(
          np.uint8(255 * mask), cv2.COLORMAP_JET
      )
      heatmap = np.float32(heatmap) / 255
      cam = heatmap + np.float32(img)
      cam = cam / np.max(cam)
      return cam
  
file_path: towhee/towhee/models/visualization/transformer_visualization.py
imports: from typing import Any
  from torch import nn
  import torch
  from torchvision import transforms
  import numpy
  from towhee.utils.pil_utils import PILImage
  from towhee.utils.cv2_utils import cv2
  from towhee.trainer.utils.file_utils import is_matplotlib_available
  from towhee.utils.log import models_log
label_desc: Use image node_id 1 for calling a global function with example usage: _add_cam_on_image(img, mask) and returns: cam