<?php
if(isset($_POST['upload'])){
 
  // Getting file name
  $filename = $_FILES['imagefile']['name'];
  
  // Valid extension
  $valid_ext = array('png','jpeg','jpg');
 
  // Location
  $location = "images/".$filename;
 
  // file extension
  $file_extension = pathinfo($location, PATHINFO_EXTENSION);
  $file_extension = strtolower($file_extension);
 
  // Check extension
  if(in_array($file_extension,$valid_ext)){
 
    // Compress Image
    compressImage($_FILES['imagefile']['tmp_name'],$location,60);
 
  }else{
    echo "Invalid file type.";
  }
}
 
// Compress image
function compressImage($source, $destination, $quality) {
 $quality = 60;
  $info = getimagesize($source);
 
  if ($info['mime'] == 'image/jpeg')
    $image = imagecreatefromjpeg($source);
 
  elseif ($info['mime'] == 'image/gif')
    $image = imagecreatefromgif($source);
 
  elseif ($info['mime'] == 'image/png')
    $image = imagecreatefrompng($source);
 
  imagejpeg($image, $destination, $quality);
 
}
 
?>

<?php
if(isset($_POST['upload'])){
 
  // Getting file name
  $filename = $_FILES['imagefile']['name'];
  
  // Valid extension
  $valid_ext = array('png','jpeg','jpg');
 
  // Location
  $location = "images/".$filename;
 
  // file extension
  $file_extension = pathinfo($location, PATHINFO_EXTENSION);
  $file_extension = strtolower($file_extension);
 
  // Check extension
  if(in_array($file_extension,$valid_ext)){
 
    // Compress Image
    compressImage($_FILES['imagefile']['tmp_name'],$location,60);
 
  }else{
    echo "Invalid file type.";
  }
}
 
// Compress image
function compressImage($source, $destination, $quality) {
 $quality: 0.6;
  $info = getimagesize($source);
 
  if ($info['mime'] == 'image/jpeg')
    $image = imagecreatefromjpeg($source);
 
  elseif ($info['mime'] == 'image/gif')
    $image = imagecreatefromgif($source);
 
  elseif ($info['mime'] == 'image/png')
    $image = imagecreatefrompng($source);
 
  imagejpeg($image, $destination, $quality);
 
}
 
?>