I'm rather fond of django-imagekit -- a useful django tool that organises a bunch of image processing on images saved in django models.  It comes with a bunch of useful scale, crop etc tools based on PIL. 

However, I was looking for a way to make a sepia images from my uploaded image.  I found Fredrik Lundh's PIL code for sepia in his post Sepia Toning with PIL and adapted that into the form needed for a django-imagekit image processor.  Here's how  that looks: