Django image resizing and convert before upload

Question

I searched a lot on this subject but couldn\'t really find what I need. I\'ll explain my problem :

On my website, the user can upload an image. I need to resize this

Answer 1

EDIT4 : full working code can be found here (the code below still has some mistakes)

Still fighting, but there is progress ^^ : I am trying to do the resizing and convertion in memory with PIL (and seeing the amount of questions on the subject, it seems that I am not the only one ^^). My code so far (in Models.py):

from PIL import Image as Img
import StringIO
from django.core.files import File

class Mymodel(models.Model):
#blablabla
photo = models.ImageField(uppload_to="...", blank=True)

    def save(self, *args, **kwargs):
        if self.photo:
            image = Img.open(StringIO.StringIO(self.photo.read()))
            image.thumbnail((100,100), Img.ANTIALIAS)
            output = StringIO.StringIO()
            image.save(output, format='JPEG', quality=75)
            output.seek(0)
            self.photo = File(output, self.photo.name())
        super(Mymodel, self).save(*args, **kwargs)

I have an error at "photo = File(output, photo.name())"

Thanks

EDIT : Sorry, it was a simple mistake (forgot the self.) corrected in code. Now I have the error "TypeError, 'unicode' object is not callable", at the same line.

EDIT2: Saw something about "output.getvalue()" here but don't really know if could be of any help.

EDIT3 : Solved!! Code below.

from PIL import Image as Img
import StringIO
from django.core.files.uploadedfile import InMemoryUploadedFile

class Mymodel(models.Model):
    photo = models.ImageField(upload_to="...", blank=True)

    def save(self, *args, **kwargs):
        if self.photo:
            image = Img.open(StringIO.StringIO(self.photo.read()))
            image.thumbnail((200,200), Img.ANTIALIAS)
            output = StringIO.StringIO()
            image.save(output, format='JPEG', quality=75)
            output.seek(0)
            self.photo= InMemoryUploadedFile(output,'ImageField', "%s.jpg" %self.photo.name, 'image/jpeg', output.len, None)
        super(Mymodel, self).save(*args, **kwargs)

For PNG looking weird, see second post on this thread

Answer 2

Here is an app that can take care of that: django-smartfields. It will also remove an old image whenever a new one is uploaded.

from django.db import models

from smartfields import fields
from smartfields.dependencies import FileDependency
from smartfields.processors import ImageProcessor

class ImageModel(models.Model):
    image = fields.ImageField(dependencies=[
        FileDependency(processor=ImageProcessor(
            format='JPEG', scale={'max_width': 300, 'max_height': 300}))
    ])