read images from dir

<?php
$images = array(); // Array-Variable definieren
	$folder = "assets/images/about/";
	$dir = openDir($folder);
	while ($file = readDir($dir)) {
	 if ($file != "." && $file != ".." && !is_dir($file) && strpos($file, ".") > 0) {
	  if (strstr($file, ".gif") ||
	      strstr($file, ".png") ||
	      strstr($file, ".jpg")) {
	   $folder_file = $folder . $file;
	   array_push($images, array(fileMtime($folder_file), $folder_file));
	  }
	 }
	}
	closeDir($dir);
	
	rsort($images); // Array sortieren
	// Array auslesen und anzeigen
	foreach ($images as $key => $value) {
	 echo '<img src="'.$images[$key][1].'" />';
	}
?>