$re = '/background\-image:(?: {1,}|)url(?: {1,}|)\([\'|"](.*)[\'|"]\)/';
$str = '<table style="background-image: url(\'http://www1.xup.to/exec/ximg.php?fid=18248939\'); background-size: 100% auto; height: 1075px;" width="772">';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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