The question about the type of the depth image

[958117216]

Shouldn't the type of the depth image from D435i be CV_16UC1, represening 0~65535mm？

There is no unit conversion，so I want to ask why CV_8UC1 is used here?

  /* init depth image */
  cv::Mat depth_gray_u8(msg->height, msg->width, CV_8UC1);
  depth_gray_ = cv::Mat::zeros(cv::Size(msg->height, msg->width), CV_8UC1);