Base64 Field for django-rest-framework

import base64, imghdr, uuid

from django.core.files.base import ContentFile
from django.utils.translation import ugettext_lazy as _
from rest_framework import serializers

DEFAULT_CONTENT_TYPE = "application/octet-stream"
ALLOWED_IMAGE_TYPES = (
    "jpeg",
    "jpg",
    "png"
    )

class Base64ImageField(serializers.ImageField):
    """
    A django-rest-framework field for handling image-uploads through raw post data.
    It uses base64 for en-/decoding the contents of the file.
    """

    def from_native(self, base64_data):
        # Check if this is a base64 string
        if isinstance(base64_data, basestring):
            # Try to decode the file. Return validation error if it fails.
            try:
                decoded_file = base64.b64decode(base64_data)
            except TypeError:
                raise serializers.ValidationError(_("Please upload a valid image."))

            # Generate file name:
            file_name = str(uuid.uuid4())[:12] # 12 character is more than enough.
            # Get the file name extension:
            file_extension = self.get_file_extension(file_name, decoded_file)
            if file_extension not in ALLOWED_IMAGE_TYPES:
                raise serializers.ValidationError(_("The type of the image couldn't been determined."))

            complete_file_name = file_name + "." + file_extension

            data = ContentFile(decoded_file, name=complete_file_name)

        return super(Base64ImageField, self).from_native(data)

    def get_file_extension(self, filename, decoded_file):
        extension = imghdr.what(filename, decoded_file)
        extension = "jpg" if extension == "jpeg" else extension
        return extension