title: Django image resizing and convert before upload
body: <p>I searched a lot on this subject but couldn't really find what I need. I'll explain my problem :</p>
  
  <p>On my website, the user can upload an image. I need to resize this image and convert it to JPEG <strong><em>before</em></strong> uploading it.</p>
  
  <p>I saw some solutions using a method in the Views.py, but I'd like to do it by overriding the save() method in my Models.py. The problem is, all solutions I found for resizing image in save method do it after saving it a first time (calling super fonction), which means it'd use bandwidth (if I use a CDN) for nothing (am I right on this point?).</p>
  
  <p>Thank you for your help</p>