Find image extension in php

$extension = substr(strrchr($current_image, '.'), 1);  if (($extension!= "jpg") && ($extension != "jpeg")&&($extension != "png")&&($extension != "gif"))
{
//error if image is not as per format
$error=1;
header("location:addpackage.php?result=image");
die();
}

 

$time = date("fYhis");

  $new_image = $time . "." . $extension;