Django thumbnail

django-thumbnail.py

# add the following util.py to your application directory

# in the models.py
from .util import create_thumbnail

class Article(models.Model):
    image = models.ImageField(default="")
    thumbnail = models.ImageField()
    def save(self):
        # create a thumbnail
        size = (200,200)
        create_thumbnail(self.image, self.thumbnail, size)
        super(Article, self).save()

util.py

def create_thumbnail(original, thumb, size):
    # original code for this method came from
    # http://www.yilmazhuseyin.com/blog/dev/create-thumbnails-imagefield-django/

    # If there is no image associated with this.
    # do not create thumbnail
    if not original:
        return

    from PIL import Image
    from cStringIO import StringIO
    from django.core.files.uploadedfile import SimpleUploadedFile
    import os

    # Set our max thumbnail size in a tuple (max width, max height)
    THUMBNAIL_SIZE = size

    DJANGO_TYPE = original.file.content_type

    if DJANGO_TYPE == 'image/jpeg':
        PIL_TYPE = 'jpeg'
        FILE_EXTENSION = 'jpg'
    elif DJANGO_TYPE == 'image/png':
        PIL_TYPE = 'png'
        FILE_EXTENSION = 'png'

    # Open original photo which we want to thumbnail using PIL's Image
    image = Image.open(StringIO(original.read()))

    # Convert to RGB if necessary
    # Thanks to Limodou on DjangoSnippets.org
    # http://www.djangosnippets.org/snippets/20/
    #
    # I commented this part since it messes up my png files
    #
    #if image.mode not in ('L', 'RGB'):
    #    image = image.convert('RGB')

    # We use our PIL Image object to create the thumbnail, which already
    # has a thumbnail() convenience method that contrains proportions.
    # Additionally, we use Image.ANTIALIAS to make the image look better.
    # Without antialiasing the image pattern artifacts may result.
    image.thumbnail(THUMBNAIL_SIZE, Image.ANTIALIAS)

    # Save the thumbnail
    temp_handle = StringIO()
    image.save(temp_handle, PIL_TYPE)
    temp_handle.seek(0)

    # Save image to a SimpleUploadedFile which can be saved into
    # ImageField
    suf = SimpleUploadedFile(os.path.split(original.name)[-1],
            temp_handle.read(), content_type=DJANGO_TYPE)
    # Save SimpleUploadedFile into image field
    thumb.save('%s_thumbnail.%s'%(os.path.splitext(suf.name)[0],FILE_EXTENSION), suf, save=False)