Compress images with Pillow in Django

You can override save method of the model:

from PIL import Image

class Photo(models.Model):
    name = models.CharField(max_length=100, null=True, blank=True, verbose_name=_("Name"))
    album = models.ForeignKey(Album, on_delete=models.PROTECT, related_name='photos', verbose_name=_("Album"))
    photo = models.ImageField(verbose_name=_("Photo"))

    def save(self, *args, **kwargs):
       instance = super(Photo, self).save(*args, **kwargs)
       image = Image.open(instance.photo.path)
       image.save(instance.photo.path,quality=20,optimize=True)
       return instance