code: def _color_im_callback(self, msg):
          
          try:
              data = self._bridge.imgmsg_to_cv2(msg)
              if np.max(data) > 255.0:
                  data = 255.0 * data / 1200.0 # Experimentally set value for white
              data = np.clip(data, 0., 255.0).astype(np.uint8)
              gsimage = GrayscaleImage(data, frame=self._frame)
              self._cur_color_im = gsimage.to_color()
          except:
              self._cur_color_im = None
docs: Callback for handling textures (greyscale images).