PHP Decode

<?php 
 
function captcha($config = array()) { 
	 
	// Check for GD library 
	if( !function_exists('gd_info') ) { 
		throw new Exception('Required GD library is missing'); 
	} 
	 
	// Default values 
	$captcha_config = array( 
		'code' => '', 
		'min_length' => 6, 
		'max_length' => 6, 
		'png_backgrounds' => array(dirname(__FILE__) . '/img/captcha.png'), 
		'fonts' => array(dirname(__FILE__) . '/img/RosewoodStd-Regular.otf'), 
		'characters' => 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789', 
		'min_font_size' => 24, 
		'max_font_size' => 30, 
		'color' => '#000', 
		'angle_min' => 0, 
		'angle_max' => 10, 
		'shadow' => true, 
		'shadow_color' => '#CCC', 
		'shadow_offset_x' => -5, 
		'shadow_offset_y' => 5 
	); 
	 
	// Overwrite defaults with custom config values 
	if( is_array($config) ) { 
		foreach( $config as $key => $value ) $captcha_config[$key] = $value; 
	} 
	 
	// Restrict certain values 
	if( $captcha_config['min_length'] < 1 ) $captcha_config['min_length'] = 1; 
	if( $captcha_config['angle_min'] < 0 ) $captcha_config['angle_min'] = 0; 
	if( $captcha_config['angle_max'] > 10 ) $captcha_config['angle_max'] = 10; 
	if( $captcha_config['angle_max'] < $captcha_config['angle_min'] ) $captcha_config['angle_max'] = $captcha_config['angle_min']; 
	if( $captcha_config['min_font_size'] < 10 ) $captcha_config['min_font_size'] = 10; 
	if( $captcha_config['max_font_size'] < $captcha_config['min_font_size'] ) $captcha_config['max_font_size'] = $captcha_config['min_font_size']; 
	 
	// Use milliseconds instead of seconds 
	srand(microtime() * 100); 
	 
	// Generate CAPTCHA code if not set by user 
	if( empty($captcha_config['code']) ) { 
		$captcha_config['code'] = ''; 
		$length = rand($captcha_config['min_length'], $captcha_config['max_length']); 
		while( strlen($captcha_config['code']) < $length ) { 
			$captcha_config['code'] .= substr($captcha_config['characters'], rand() % (strlen($captcha_config['characters'])), 1); 
		} 
	} 
	 
	// Generate image src 
	$image_src = substr(__FILE__, strlen($_SERVER['DOCUMENT_ROOT'])) . '?_CAPTCHA&amp;t=' . urlencode(microtime()); 
	$image_src = '/' . ltrim(preg_replace('/\\/', '/', $image_src), '/'); 
	 
	$_SESSION['_CAPTCHA']['config'] = serialize($captcha_config); 
	 
	return array( 
		'code' => $captcha_config['code'], 
		'image_src' => $image_src 
	); 
 
} 
 
 
if( !function_exists('hex2rgb') ) { 
	function hex2rgb($hex_str, $return_string = false, $separator = ',') { 
		$hex_str = preg_replace("/[^0-9A-Fa-f]/", '', $hex_str); // Gets a proper hex string 
		$rgb_array = array(); 
		if( strlen($hex_str) == 6 ) { 
			$color_val = hexdec($hex_str); 
			$rgb_array['r'] = 0xFF & ($color_val >> 0x10); 
			$rgb_array['g'] = 0xFF & ($color_val >> 0x8); 
			$rgb_array['b'] = 0xFF & $color_val; 
		} elseif( strlen($hex_str) == 3 ) { 
			$rgb_array['r'] = hexdec(str_repeat(substr($hex_str, 0, 1), 2)); 
			$rgb_array['g'] = hexdec(str_repeat(substr($hex_str, 1, 1), 2)); 
			$rgb_array['b'] = hexdec(str_repeat(substr($hex_str, 2, 1), 2)); 
		} else { 
			return false; 
		} 
		return $return_string ? implode($separator, $rgb_array) : $rgb_array; 
	} 
} 
 
 
// Draw the image 
if( isset($_GET['_CAPTCHA']) ) { 
	 
	session_start(); 
	 
	$captcha_config = unserialize($_SESSION['_CAPTCHA']['config']); 
	unset($_SESSION['_CAPTCHA']); 
	 
	// Use milliseconds instead of seconds 
	srand(microtime() * 100); 
	 
	// Pick random background, get info, and start captcha 
	$background = $captcha_config['png_backgrounds'][rand(0, count($captcha_config['png_backgrounds']) -1)]; 
	list($bg_width, $bg_height, $bg_type, $bg_attr) = getimagesize($background); 
	 
	// Create captcha object 
	$captcha = imagecreatefrompng($background); 
    imagealphablending($captcha, true); 
    imagesavealpha($captcha , true); 
	 
	$color = hex2rgb($captcha_config['color']); 
	$color = imagecolorallocate($captcha, $color['r'], $color['g'], $color['b']); 
         
	// Determine text angle 
	$angle = rand( $captcha_config['angle_min'], $captcha_config['angle_max'] ) * (rand(0, 1) == 1 ? -1 : 1); 
	 
	// Select font randomly 
	$font = $captcha_config['fonts'][rand(0, count($captcha_config['fonts']) - 1)]; 
	 
	// Verify font file exists 
	if( !file_exists($font) ) throw new Exception('Font file not found: ' . $font); 
	 
	//Set the font size. 
	$font_size = rand($captcha_config['min_font_size'], $captcha_config['max_font_size']); 
	$text_box_size = imagettfbbox($font_size, $angle, $font, $captcha_config['code']); 
	 
	// Determine text position 
	$box_width = abs($text_box_size[6] - $text_box_size[2]); 
	$box_height = abs($text_box_size[5] - $text_box_size[1]); 
	$text_pos_x_min = 0; 
	$text_pos_x_max = ($bg_width) - ($box_width); 
	$text_pos_x = rand($text_pos_x_min, $text_pos_x_max);			 
	$text_pos_y_min = $box_height; 
	$text_pos_y_max = ($bg_height) - ($box_height / 2); 
	$text_pos_y = rand($text_pos_y_min, $text_pos_y_max); 
	 
	// Draw shadow 
	if( $captcha_config['shadow'] ){ 
		$shadow_color = hex2rgb($captcha_config['shadow_color']); 
	 	$shadow_color = imagecolorallocate($captcha, $shadow_color['r'], $shadow_color['g'], $shadow_color['b']); 
		imagettftext($captcha, $font_size, $angle, $text_pos_x + $captcha_config['shadow_offset_x'], $text_pos_y + $captcha_config['shadow_offset_y'], $shadow_color, $font, $captcha_config['code']);	 
	} 
	 
	// Draw text 
	imagettftext($captcha, $font_size, $angle, $text_pos_x, $text_pos_y, $color, $font, $captcha_config['code']);	 
	 
	// Output image 
	header("Content-type: image/png"); 
	imagepng($captcha); 
	 
} 
$_SESSION['captcha'] = captcha(); 
$_SESSION['ccode'] = $captcha_config['code']; 
?>