Mine

	$pattern = '/<img src="[^>]*"[^>]*width="[' . $widthLimitInHundreds . '-9]{1}[0-9]{2,}"[^>]*>/';
	$replacement = '<a href="${1}" target="_blank"><img src="${1}" width="' . $widthLimitInHundreds * 100 . '"></a>';
	$replacement = 'zero \\0 one \\1 two \\2';
	return preg_replace($pattern, $replacement, $haystack);