class image(models.Model):
    pub_date = models.DateTimeField()
    description_src = models.TextField()
    description = models.TextField()
    image = models.ImageField(upload_to = 'images')
    def save(self, request = None):
        if request != None and request.user.has_perm('gallery.add.image'):
            self.description_src = escape(request.POST['description'])
            self.description = markdown(self.description_src)
            self.pub_date = datetime.now()
            self.image =  ????
        super(image, self).save()