Trying to reduce functionality, what should I comment?

I have the following script that automatically creates a thumbnail image gallery. All you have to do is upload images to the directory or any subdirectories and the script will create a thumbnail and link it to the image.

Well my host uses a security setting that prevents excessive use of the GD2 library to prevent dos attacks and the script does not work properly.

I don't care about resizing the image. I just want to be able to upload an image and get it to display without editing the html. What to I need to get rid of here to get that functionality.

*/

// GALLERY SETTINGS

Define('DIR_CACHE', './tmp/'); // directory to store modified images (shoul have right to write files)
Define('THUMBNAIL_WIDTH', '0'); // thumbnails width
Define('THUMBNAIL_HEIGHT', '0'); // thumbnails height
Define('IMAGES_ROW', 1); // images on row




// ----------------------------------------------------------------------





$img=$_GET['img'];

if (!Is_Dir(DIR_CACHE)) {
 mkdir(DIR_CACHE, 0777);
}

// IMAGE RESIZE AND SAVE TO FIT IN $new_width x $new_height
if ($img!='' && file_exists($img)) {

 $w=$_GET['w'];
 $h=$_GET['h'];

 $thumb=strtolower(preg_replace('/\W/is', "_", "$img $w $h"));

  $changed=0;
  if (file_exists($img) && file_exists(DIR_CACHE.$thumb)) {
   $mtime1=filemtime(DIR_CACHE.$thumb);
   $mtime2=filemtime($img);
   if ($mtime2>$mtime1) $changed=1;
  } elseif (!file_exists(DIR_CACHE.$thumb)) {
   $changed=1;
  }

 if ($changed) {

 $filename=$img;
 $new_width=(int)@$w;
 $new_height=(int)@$h;
 $lst=GetImageSize($filename);
 $image_width=$lst[0];
 $image_height=$lst[1];
 $image_format=$lst[2];

 if ($image_format==1) {
   Header("Content-Type:image/gif");
   readfile($filename);
   exit;
 } elseif ($image_format==2) {
  $old_image=imagecreatefromjpeg($filename);
 } elseif ($image_format==3) {
  $old_image=imagecreatefrompng($filename);
 } else {
  exit;
 }

 if (($new_width!=0) && ($new_width<$image_width)) {
  $image_height=(int)($image_height*($new_width/$image_width));
  $image_width=$new_width;
//  $image_height=$new_height;
 }

 if (($new_height!=0) && ($new_height<$image_height)) {
  $image_width=(int)($image_width*($new_height/$image_height));
  $image_height=$new_height;
//  $image_width=$new_width;
 }


//  $new_image=imageCreate($image_width, $image_height); // for old GDlib
 $new_image=imageCreateTrueColor($image_width, $image_height);

 $white = ImageColorAllocate($new_image, 255, 255, 255);
 ImageFill($new_image, 0, 0, $white);

// imagecopyresampled
// imageCopyResized (for old GDlib)
 imageCopyResampled( $new_image, $old_image, 0, 0, 0, 0, $image_width, $image_height, imageSX($old_image), imageSY($old_image));

 imageJpeg($new_image, DIR_CACHE.$thumb);
 }


 Header("Content-type:image/jpeg");
 readfile(DIR_CACHE.$thumb);
 exit;
}

// ----------------------------------------------------------------------

  $init_dir="./";

  if (IsSet($HTTP_GET_VARS['dir'])) {
   $dir=$HTTP_GET_VARS['dir'];
   $dir=preg_replace("/\.+/", ".", $dir);
  }

  if (IsSet($dir) && ($dir!=$init_dir)) {
   $directory=$dir;
   $tmp=array_reverse(explode('/', $dir));
   array_shift($tmp);
   array_shift($tmp);
   $out['UP']=urlencode(implode('/', array_reverse($tmp))."/");
  } else {
   $directory=$init_dir;
  }

  $dir=opendir($directory);
  $k=0;
  $on_row=IMAGES_ROW;


  if (file_exists($directory."files.txt")) {
   $data=LoadFile($directory."files.txt");
   $lines=explode("\n", $data);
   for($i=0;$i<count($lines);$i++) {
    $ar=explode(' ', trim($lines[$i]));
    $tmp=array_shift($ar);
    $descriptions[$tmp]=implode(' ', $ar);
   }
  }

  while ($file=readdir($dir)) { 
   if (Is_Dir($directory."/$file") && ($file!='tmp') && ($file!='.') && ($file!='..')) {
    $directories[]=array('FILENAME'=>$file, 'DIR'=>$directory, 'DESCRIPTION'=>$descriptions[$file], 'URL'=>urlencode($directory."$file/"));
   }
   
   if (!Is_file($directory."/$file")) continue;

   $ext=strtolower(substr($file, -3));

   if ($ext!='gif' && $ext!='jpg') continue;

   $rec=array();
   $rec["FILENAME"]=$file;

   $size=(int)(filesize($directory."/".$file)/1024);
   if ($size>1024) {
    $rec["SIZE"]=(((int)($size*100/1024))/100)." Mb";
   } else {
    $rec["SIZE"]=$size." Kb";
   }
   if (IsSet($descriptions[$file])) {
    $rec['DESCRIPTION']=$descriptions[$file];
   }
   $rec["DIR"]=$directory;
   if (($k+1)%$on_row==0) {
    $rec['NEXT_ROW']=1;
   }
   $k++;
   $files[]=$rec;
  }

  include('./template.php');

// ----------------------------------------------------------------------

function LoadFile($filename) {
 // loading file
 $f=fopen("$filename", "r");
 $data="";
 if ($f) {
  $data=fread($f, filesize($filename));
  fclose($f);
 }
 return $data;
}


?>

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