BarcodeGenerator::qr_penalty_4

private function qr_penalty_4(&$matrix, $size) {
	$dark = 0;
	for ($i = 0; $i < $size; $i++) {
		for ($j = 0; $j < $size; $j++) {
			if ($matrix[$i][$j] == 5 || $matrix[$i][$j] == 3) {
				$dark++;
			}
		}
	}
	$dark *= 20;
	$dark /= $size * $size;
	$a = abs(floor($dark) - 10);
	$b = abs(ceil($dark) - 10);
	return min($a, $b) * 10;
}