code: def frames(self, most_recent=False):
          
          if most_recent:
              for i in xrange(4):
                  self._cap.grab()
          for i in range(1):
              if self._adjust_exposure:
                  try:
                      command = 'v4l2-ctl -d /dev/video{} -c exposure_auto=1 -c exposure_auto_priority=0 -c exposure_absolute=100 -c saturation=60 -c gain=140'.format(self._device_id)
                      FNULL = open(os.devnull, 'w')
                      subprocess.call(shlex.split(command), stdout=FNULL, stderr=subprocess.STDOUT)
                  except:
                      pass
              ret, frame = self._cap.read()
          rgb_data = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
  
          return ColorImage(rgb_data, frame=self._frame), None, None
docs: Retrieve a new frame from the PhoXi and convert it to a ColorImage,
          a DepthImage, and an IrImage.
  
          Parameters
          ----------
          most_recent: bool
              If true, the OpenCV buffer is emptied for the webcam before reading the most recent frame.
  
          Returns
          -------
          :obj:`tuple` of :obj:`ColorImage`, :obj:`DepthImage`, :obj:`IrImage`, :obj:`numpy.ndarray`
              The ColorImage, DepthImage, and IrImage of the current frame.