View file services/surfing/captcha.php

<?php  
require_once ($_SERVER['DOCUMENT_ROOT'].'/system/connections/core.php'); 

$number_1 = session('rand_code1');
$number_2 = session('rand_code2');
session('rand_code', $number_1 + $number_2);
$dir = ROOT."/services/surfing/";
$image = imagecreatetruecolor(200, 60);
$color = imagecolorallocate($image, 200, 100, 90);
$white = imagecolorallocate($image, 255, 255, 255);
imagefilledrectangle($image, 0, 0, 399, 99, $white);
imagettftext ($image, 30, 0, 10, 40, $color, $dir."Arial_Regular.ttf", "$number_1 + $number_2");
header("Content-type: image/png");
imagepng($image);