$re = '/<img src="http:\/\/website\.com\/char\/sign\/(.+?)\.png">/';
$str = '<img src="http://website.com/char/sign/Name+Surname.png">, <img src="http://website.com/char/sign/Bob-Robinson.png">, <img src="http://website.com/char/sign/Michael%2527Ross.png">';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php