BarcodeGenerator::allocate_color

private function allocate_color($image, $color) {
	$color = preg_replace('/[^0-9A-Fa-f]/', '', $color);
	switch (strlen($color)) {
		case 1:
			$v = hexdec($color) * 17;
			return imagecolorallocate($image, $v, $v, $v);
		case 2:
			$v = hexdec($color);
			return imagecolorallocate($image, $v, $v, $v);
		case 3:
			$r = hexdec(substr($color, 0, 1)) * 17;
			$g = hexdec(substr($color, 1, 1)) * 17;
			$b = hexdec(substr($color, 2, 1)) * 17;
			return imagecolorallocate($image, $r, $g, $b);
		case 4:
			$a = hexdec(substr($color, 0, 1)) * 17;
			$r = hexdec(substr($color, 1, 1)) * 17;
			$g = hexdec(substr($color, 2, 1)) * 17;
			$b = hexdec(substr($color, 3, 1)) * 17;
			$a = round((255 - $a) * 127 / 255);
			return imagecolorallocatealpha($image, $r, $g, $b, $a);
		case 6:
			$r = hexdec(substr($color, 0, 2));
			$g = hexdec(substr($color, 2, 2));
			$b = hexdec(substr($color, 4, 2));
			return imagecolorallocate($image, $r, $g, $b);
		case 8:
			$a = hexdec(substr($color, 0, 2));
			$r = hexdec(substr($color, 2, 2));
			$g = hexdec(substr($color, 4, 2));
			$b = hexdec(substr($color, 6, 2));
			$a = round((255 - $a) * 127 / 255);
			return imagecolorallocatealpha($image, $r, $g, $b, $a);
		default:
			return imagecolorallocatealpha($image, 0, 0, 0, 127);
	}
}