TypeError: file() argument 1 must be encoded string without NULL bytes, not str odoo - eclipse

Question

the python version is 2.8.2 and using it in eclipse. I am getting this error when I am trying to execute the following command:
The function is:
#api.one
#api.depends('image')
def _compute_image_details(self):
if self.image:
image_content = self.image.decode('base64')
print type(self.image)
print type(image_content)
# File size
self.size = len(image_content)
# Camera make and model from EXIF tags
img = PIL.Image.open(image_content)
exif_tags = img._getexif()
# 0x010f is a numeric code for the "make" exif field
# You can find a list of fields here: exiv2.org/tags.html
self.camera_maker = exif_tags.get(0x010f)
The error which is raised is:
Traceback (most recent call last):
File "/home/next/WORKSPACE/odoo-8.0/openerp/http.py", line 537, in _handle_exception
return super(JsonRequest, self)._handle_exception(exception)
File "/home/next/WORKSPACE/odoo-8.0/openerp/http.py", line 574, in dispatch
result = self._call_function(**self.params)
File "/home/next/WORKSPACE/odoo-8.0/openerp/http.py", line 310, in _call_function
return checked_call(self.db, *args, **kwargs)
File "/home/next/WORKSPACE/odoo-8.0/openerp/service/model.py", line 113, in wrapper
return f(dbname, *args, **kwargs)
File "/home/next/WORKSPACE/odoo-8.0/openerp/http.py", line 307, in checked_call
return self.endpoint(*a, **kw)
File "/home/next/WORKSPACE/odoo-8.0/openerp/http.py", line 803, in __call__
return self.method(*args, **kw)
File "/home/next/WORKSPACE/odoo-8.0/openerp/http.py", line 403, in response_wrap
response = f(*args, **kw)
File "/home/next/WORKSPACE/odoo-8.0/addons/web/controllers/main.py", line 944, in call_kw
return self._call_kw(model, method, args, kwargs)
File "/home/next/WORKSPACE/odoo-8.0/addons/web/controllers/main.py", line 936, in _call_kw
return getattr(request.registry.get(model), method)(request.cr, request.uid, *args, **kwargs)
File "/home/next/WORKSPACE/odoo-8.0/openerp/api.py", line 241, in wrapper
return old_api(self, *args, **kwargs)
File "/home/next/WORKSPACE/odoo-8.0/openerp/api.py", line 363, in old_api
result = method(recs, *args, **kwargs)
File "/home/next/WORKSPACE/odoo-8.0/openerp/models.py", line 5873, in onchange
newval = record[name]
File "/home/next/WORKSPACE/odoo-8.0/openerp/models.py", line 5571, in __getitem__
return self._fields[key].__get__(self, type(self))
File "/home/next/WORKSPACE/odoo-8.0/openerp/fields.py", line 820, in __get__
self.determine_draft_value(record)
File "/home/next/WORKSPACE/odoo-8.0/openerp/fields.py", line 928, in determine_draft_value
self._compute_value(record)
File "/home/next/WORKSPACE/odoo-8.0/openerp/fields.py", line 867, in _compute_value
self.compute(records)
File "/home/next/WORKSPACE/odoo-8.0/openerp/api.py", line 239, in wrapper
return new_api(self, *args, **kwargs)
File "/home/next/WORKSPACE/odoo-8.0/openerp/api.py", line 397, in new_api
result = [method(rec, *args, **kwargs) for rec in self]
File "/home/next/WORKSPACE/odoo-8.0/addons/transform_webservice_example/image_example.py", line 33, in _compute_image_details
img = PIL.Image.open(image_content)
File "/usr/lib/python2.7/dist-packages/PIL/Image.py", line 1955, in open
fp = __builtin__.open(fp, "rb")
TypeError: file() argument 1 must be encoded string without NULL bytes, not str
Please help me with this issue.
The other references say about the URL of the file. This is different scenario.

Answer 1

You're trying to open the base64 decoded contents of the file, you're supposed to open the file itself.
PIL.Image.open(self.image)
take this for example, to reproduce the error you're getting
>>> open('\0')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: file() argument 1 must be encoded string without NULL bytes, not str
>>>
the character '\0' is seen as a NullByte which the decoded image contains