PHP imagecreatefrompng / ImageColorAllocate / ImageTTFText

<?php

   $area = ($_GET['area']) ? $_GET['area'] : "";
   $name = ($_GET['name']) ? $_GET['name'] : "이름없음";
   $font = $_SERVER['DOCUMENT_ROOT'].'/fonts/font1.ttf';
   $size = "80";


   switch($area){
      case "서울시":
         break;
      case "경기도":
         break;
      case "인천시":
         break;
      case "충청북도":
         $img = $_SERVER['DOCUMENT_ROOT']."/UPLOAD/area/back3.png";
         $im2  = imagecreatefrompng($img);
         $gray = ImageColorAllocate($im2,80,80,80);
         ImageTTFText($im2,$size,0,imagesx($im2)-400,imagesy($im2)-170,$gray,$font,$name); 
         break;
      case "충청남도":
         break;
      case "대전시":
         break;
      case "세종시":
         break;
      case "경상북도":
         break;
      case "경상남도":
         break;
      case "대구시":
         break;
      case "울산시":
         break;
      case "부산시":
         break;
      case "강원도":
         break;
      case "전라북도":
         break;
      case "전라남도":
         break;
      case "전주시":
         break;
      case "광주시":
         break;
      case "제주도":
         break;
   }

   header('Content-Type: image/png');
   $filename = "{$name}_서약서.png";
   $filepath = $_SERVER['DOCUMENT_ROOT']."/UPLOAD/pledge/{$filename}";
   imagepng($im2, $filepath);
   imagedestroy($im2);

   $filesize = filesize($filepath);
   header("Pragma: public");
   header("Expires: 0");
   header("Content-Type: application/octet-stream");
   header("Content-Disposition: attachment; filename={$filename}");
   header("Content-Transfer-Encoding: binary");
   header("Content-Length: $filesize");

   ob_clean();
   flush();
   readfile($filepath);

?>