public function bitImage(EscposImage $img, $size = Printer::IMG_DEFAULT)
{
self::validateInteger($size, 0, 3, __FUNCTION__);
$rasterData = $img->toRasterFormat();
$header = Printer::dataHeader(array($img->getWidthBytes(), $img->getHeight()), true);
$this->connector->write(self::GS . "v0" . chr($size) . $header);
$this->connector->write($rasterData);
}