See ISO 18004:2006, 6.5.1. This enum encapsulates the four error correction levels * defined by the QR code standard.

* * @author Sean Owen */ class ErrorCorrectionLevel { private static $FOR_BITS; private $bits; private $ordinal; public function __construct($bits, $ordinal = 0) { $this->bits = $bits; $this->ordinal = $ordinal; } public static function Init() { self::$FOR_BITS = [ new ErrorCorrectionLevel(0x00, 1), //M new ErrorCorrectionLevel(0x01, 0), //L new ErrorCorrectionLevel(0x02, 3), //H new ErrorCorrectionLevel(0x03, 2), //Q ]; } /** L = ~7% correction */ // self::$L = new ErrorCorrectionLevel(0x01); /** M = ~15% correction */ //self::$M = new ErrorCorrectionLevel(0x00); /** Q = ~25% correction */ //self::$Q = new ErrorCorrectionLevel(0x03); /** H = ~30% correction */ //self::$H = new ErrorCorrectionLevel(0x02); /** * @param bits int containing the two bits encoding a QR Code's error correction level * * @return ErrorCorrectionLevel representing the encoded error correction level */ public static function forBits($bits) { if ($bits < 0 || $bits >= count(self::$FOR_BITS)) { throw new \InvalidArgumentException(); } $level = self::$FOR_BITS[$bits]; // $lev = self::$$bit; return $level; } public function getBits() { return $this->bits; } public function toString() { return $this->bits; } public function getOrdinal() { return $this->ordinal; } } ErrorCorrectionLevel::Init();