在Django中保存已处理的图像

Question

我在实施此处建议的解决方案时遇到问题： PIL thumbnail is rotating my image?

我的情况略有不同，因为我正在使用用户上传的文件。这是我的观点：

from PIL import Image, ExifTags

def add_work_image(request, work_id=None):
    image = WorkImage()
    image.owner = request.user.profile
    image.sort_index = int(request.POST.get('image_order')[0])

    source_image = request.FILES.get('image_file')

    try:
        opened_image = Image.open(source_image)
        if hasattr(opened_image, '_getexif'): # only present in JPEGs
            for orientation in ExifTags.TAGS.keys():
                if ExifTags.TAGS[orientation]=='Orientation':
                    break
            e = opened_image._getexif()       # returns None if no EXIF data
            if e is not None:
                exif=dict(e.items())
                orientation = exif[orientation]
                print("***** orientation")
                print(orientation)

                if orientation == 3:
                    opened_image = opened_image.transpose(Image.ROTATE_180)
                elif orientation == 6:
                    opened_image = opened_image.transpose(Image.ROTATE_270)
                elif orientation == 8:
                    opened_image = opened_image.transpose(Image.ROTATE_90)

                new_image_io = BytesIO()
                opened_image.save(new_image_io, format='JPEG')
        image.image = opened_image
    except Exception as e:
        print str(e)
        image.image = source_image

    if work_id:
        work = get_object_or_404(Work, pk=work_id)
        image.work = work

    image.save()

    return JsonResponse({
        'image_src': image.get_absolute_url(size='work_image'),
        'image_id': image.pk})

我不熟悉Django / Python如何处理上传的文件。我在这里缺少什么？

更新了更清晰：

以下是模型：

from django_images.models import Image

class WorkImage(Image):

    @classmethod
    def get_orphan_images_for_profile(cls, profile, limit=4):
        return WorkImage.objects.filter(
            work__isnull = True,
            owner__pk = profile.pk
        ).order_by('sort_index', '-created_at').all()[:limit]

    work = models.ForeignKey(
        Work,
        related_name = 'images',
        null = True,
        on_delete=models.CASCADE
        )

    owner = models.ForeignKey(
        UserProfile)

    sort_index = models.IntegerField()

该模型正在使用此django-images。以前，调用image.image = request.FILES.get('image_file')工作得很好。

我看到的错误：

（原始）

AttributeError: _committed
  File "django/core/handlers/base.py", line 149, in get_response
    response = self.process_exception_by_middleware(e, request)
  File "django/core/handlers/base.py", line 147, in get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "django/contrib/auth/decorators.py", line 23, in _wrapped_view
    return view_func(request, *args, **kwargs)
  File "django/views/decorators/http.py", line 42, in inner
    return func(request, *args, **kwargs)
  File "availableworks/utils.py", line 35, in wrapper
    return f(request, *args, **kwargs)
  File "availableworks/utils.py", line 58, in wrapper
    return f(request, *args, **kwargs)
  File "availableworks/account/views/works.py", line 78, in add_work_image
    image.save()
  File "django/db/models/base.py", line 700, in save
    force_update=force_update, update_fields=update_fields)
  File "django/db/models/base.py", line 727, in save_base
    self._save_parents(cls, using, update_fields)
  File "django/db/models/base.py", line 752, in _save_parents
    self._save_table(cls=parent, using=using, update_fields=update_fields)
  File "django/db/models/base.py", line 812, in _save_table
    result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
  File "django/db/models/base.py", line 851, in _do_insert
    using=using, raw=raw)
  File "django/db/models/manager.py", line 122, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "django/db/models/query.py", line 1039, in _insert
    return query.get_compiler(using=using).execute_sql(return_id)
  File "django/db/models/sql/compiler.py", line 1059, in execute_sql
    for sql, params in self.as_sql():
  File "django/db/models/sql/compiler.py", line 1019, in as_sql
    for obj in self.query.objs
  File "django/db/models/sql/compiler.py", line 968, in pre_save_val
    return field.pre_save(obj, add=True)
  File "django/db/models/fields/files.py", line 309, in pre_save
    if file and not file._committed:
  File "PIL/Image.py", line 628, in __getattr__
    raise AttributeError(name)

（通过Sentry：）