如何将django图像场形成PIL图像并返回?

时间:2014-02-26 08:36:32

标签: django python-imaging-library imagefield

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。)

修改

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]:

2 个答案:

答案 0 :(得分:18)

要从PIL图像转到Django ImageField,我使用了falsetru的答案,但我必须为Python 3更新它。

首先,StringIO已被io替换为: StringIO in python3

其次,当我尝试io.StringIO()时,我收到了一条错误消息:"*** TypeError: string argument expected, got 'bytes'"。所以我将其更改为io.BytesIO()并且一切正常。

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()

答案 1 :(得分:14)

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()

<强>更新

根据OP的评论,用import Image替换from PIL import Image解决了他的问题。