<?php
    // Put this somewhere on the server and put these in an .htaccess file in the same folder
    //
    // Options +FollowSymLinks
    // RewriteEngine on
    // RewriteRule ^logo$ logo.php

    // Then point the image to <htaccess location>/logo. The folder logos is the default location for the logos files (accepts gif/jpg/png)

    error_reporting(E_ALL);
    $LOGOSDIR = "logos/";

    if ($handle = opendir($LOGOSDIR)) {
        $files = array();
                while (false !== ($file = readdir($handle))) {
                        $files[] = $file;
                                }
                    closedir($handle);
    }
    $files = preg_grep('/(png|gif|jpg|jpeg)$/', $files);
    $fullPath = $LOGOSDIR . $files[array_rand($files)];
        $path_parts = pathinfo($fullPath);
    $ext = strtolower($path_parts["extension"]);

    switch ($ext) {
      case "gif": $ctype="image/gif"; break;
      case "png": $ctype="image/png"; break;
      case "jpeg":
      case "jpg": $ctype="image/jpg"; break;
      default: $ctype="application/force-download";
    }
    header("Expires: " . date('r',strtotime("+1 days")));
    header("Pragma: cache");
    header("Cache-Control: max-age=86400");
    header("Content-Type: " . $ctype);
    header("Content-Length: " . filesize($fullPath));
    header("Last-Modified: " . date('r',strtotime("today")));
    readfile($fullPath);
?>