code: def median_depth_img(self, num_img=1):
          
          depths = []
  
          for _ in range(num_img):
              _, depth, _ = self.frames()
              depths.append(depth)
  
          return Image.median_images(depths)
docs: Collect a series of depth images and return the median of the set.
  
          Parameters
          ----------
          num_img : int
              The number of consecutive frames to process.
  
          Returns
          -------
          :obj:`DepthImage`
              The median DepthImage collected from the frames.