A Simple PHP Thumbnail Image Resize Script

Step 1: To create Test.php & copy paste below code

<?php


session_start();
header("Pragma: public");
header("Cache-Control: max-age = 604800");
header("Expires: ".gmdate("D, d M Y H:i:s", time() + 604800)." GMT");

function thumbnail($image, $width, $height) {

 if($image[0] != "/") { // Decide where to look for the image if a full path is not given
  if(!isset($_SERVER["HTTP_REFERER"])) { // Try to find image if accessed directly from this script in a browser
   $image = $_SERVER["DOCUMENT_ROOT"].implode("/", (explode('/', $_SERVER["PHP_SELF"], -1)))."/".$image;
  } else {
   $image = implode("/", (explode('/', $_SERVER["HTTP_REFERER"], -1)))."/".$image;
  }
 } else {
  $image = $_SERVER["DOCUMENT_ROOT"].$image;
 }
 $image_properties = getimagesize($image);
 $image_width = $image_properties[0];
 $image_height = $image_properties[1];
 $image_ratio = $image_width / $image_height;
 $type = $image_properties["mime"];

 if(!$width && !$height) {
  $width = $image_width;
  $height = $image_height;
 }
 if(!$width) {
  $width = round($height * $image_ratio);
 }
 if(!$height) {
  $height = round($width / $image_ratio);
 }

 if($type == "image/jpeg") {
  header('Content-type: image/jpeg');
  $thumb = imagecreatefromjpeg($image);
 } elseif($type == "image/png") {
  header('Content-type: image/png');
  $thumb = imagecreatefrompng($image);
 } else {
  return false;
 }

 $temp_image = imagecreatetruecolor($width, $height);
 imagecopyresampled($temp_image, $thumb, 0, 0, 0, 0, $width, $height, $image_width, $image_height);
 $thumbnail = imagecreatetruecolor($width, $height);
 imagecopyresampled($thumbnail, $temp_image, 0, 0, 0, 0, $width, $height, $width, $height);

 if($type == "image/jpeg") {
  imagejpeg($thumbnail);
 } else {
  imagepng($thumbnail);
 }

 imagedestroy($temp_image);
 imagedestroy($thumbnail);

}

if(isset($_GET["h"])) { $h = $_GET["h"]; } else { $h = 0; }
if(isset($_GET["w"])) { $w = $_GET["w"]; } else { $w = 0; }

thumbnail($_GET["img"], $w, $h);

?>


Step 2: Index.php