Afficher dossier contenant des images

<?php
 
$a = 0;
$handle = opendir("chemin/dossier"); 

         $dir = opendir("chemin/dossier");
         while($file = readdir($dir)){
            if(!in_array($file,array(".",".."))){
               $files_array[] = $file;
            }
         }
         natcasesort($files_array);
         foreach($files_array as $file)
  {
  echo "<p><a href=\"chemin/dossier/$file\">","chemin/dossier/$file","</a></p>";
  $a++;
  }

closedir($handle); 
?>