php 读取目录下图像文件

$directory = 'gallery';

$allowed_types=array('jpg','jpeg','gif','png');
$file_parts=array();
$ext='';
$title='';
$i=0;

$dir_handle = @opendir($directory) or die("there is an error with your image directory!");

while ($file = readdir($dir_handle))
{
 if($file=='.' || $file == '..') continue;
 
 $file_parts = explode('.',$file);
 $ext = strtolower(array_pop($file_parts));

 $title = implode('.',$file_parts);
 $title = htmlspecialchars($title);
 
 $nomargin='';
 
 if(in_array($ext,$allowed_types))
 {
  if(($i+1)%4==0) $nomargin='nomargin';
 
  echo '
  

closedir($dir_handle);