read images of directory

$folder = opendir("."); // Use 'opendir(".")' if the PHP file is in the same folder as your images. Or set a relative path 'opendir("../path/to/folder")'.
 
$pic_types = array("jpg", "jpeg", "gif", "png");
 
$index = array();
 
while ($file = readdir ($folder)) {
 
  if(in_array(substr(strtolower($file), strrpos($file,".") + 1),$pic_types))
	{
		array_push($index,$file);
	}
}
 
closedir($folder);