The old function uses PIL to save the image, which is not in the requirements file. As we are already requiring opencv, use that to save images instead of an additional dependency Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>