如何将django图像场形成PIL图像并返回？

Question

给定django图像字段,如何创建PIL图像,反之亦然？

简单的问题,但很难谷歌:(

(我将使用django-imagekit的处理器来旋转已经存储为模型属性的图像.)

编辑

In [41]: m.image_1.__class__
Out[41]: django.db.models.fields.files.ImageFieldFile

In [42]: f = StringIO(m.image_1.read())

In [43]: Image.open(f)
---------------------------------------------------------------------------
IOError                                   Traceback (most recent call last)
<ipython-input-43-39949b3b74b3> in <module>()
----> 1 Image.open(f)

/home/eugenekim/virtualenvs/zibann/local/lib/python2.7/site-packages/PIL/Image.pyc in open(fp, mode)
   2023                 pass
   2024
-> 2025     raise IOError("cannot identify image file")
   2026
   2027 #

IOError: cannot identify image file

In [44]:

Answer 1

要从PIL图像转到Django ImageField,我使用了falsetru的答案,但我不得不为Python 3更新它.

首先,StringIO已经被io替换为 python3中的StringIO

第二,当我尝试时io.StringIO(),我收到一个错误说:"*** TypeError: string argument expected, got 'bytes'".所以我把它改成了,io.BytesIO()一切都奏效了.

from PIL import Image
from io import BytesIO
from django.core.files.base import ContentFile

f = BytesIO()
try:
    pil_image_obj.save(f, format='png')
    model_instance.image_field.save(model_instance.image_field.name,
                                   ContentFile(f.getvalue()))
#model_instance.save()
finally:
    f.close()

Answer 2

第一个问题:

import Image

pil_image_obj = Image.open(model_instance.image_field)

第二个问题:

from cStringIO import StringIO
from django.core.files.base import ContentFile

f = StringIO()
try:
    pil_image_obj.save(f, format='png')
    s = f.getvalue()
    model_instance.image_field.save(model_instance.image_field.name,
                                    ContentFile(s))
    #model_instance.save()
finally:
    f.close()

UPDATE

据OP的评论,替换import Image与from PIL import Image解决他的问题.