使用imagecreatefromjpeg上传的图像后重定向

Question

I'm currently trying to use the GD library to crop and upload an image. I upload the image first to the server and save the url to the image which I then pass to the following script which reads the original uploaded image and it crops it according to the coordinate that I give it.

<?php

   $w = $h = 150;
   $quality = 90;

   $src = $_POST['path'];
   $img = imagecreatefromjpeg($src);
   $kak = ImageCreateTrueColor( $w, $h );
   imagecopyresampled($kak,$img,0,0,$_POST['x'],$_POST['y'],
   $w,$h,$_POST['w'],$_POST['h']);

   header('Content-type: image/jpeg');
   imagejpeg($kak,'c.jpg',$quality);
   imagedestroy($img);
?>

All works fine, image upload, crop and cropped image upload. The problem is that this page is completely empty and I would like to redirect the visitor to a different page but if I add

header ("Location: nextpage.php");

at the end of my php script it obviously redirects before finishing uploading. Does anyone know how to do this once the file has been uploaded successfully?

Thanks in advance