Add the channel information to the channel_data attribute.

def _process_channels(self,p,**params_to_override):
        """
        Add the channel information to the channel_data attribute.
        """
        orig_image = self._image

        for i in range(len(self._channel_data)):
            self._image = self._original_channel_data[i]
            self._channel_data[i] = self._reduced_call(**params_to_override)
        self._image = orig_image
        return self._channel_data