UnicodeDecodeError. While rendering the blob image
===

I am trying to add uploading images feature.
This class saves new entity:
 
    class NewPost(Handler):
        def render_newpost(self, title='' , content='', error = ''):
            self.render("newpost.html", title = title, content = content, error = error)
            
    
        def get(self):
            user_cookie = self.request.cookies.get('user')
            if user_cookie:
                user_id = user_cookie.split('|')[0]
                if hash_str(user_id) == user_cookie.split('|')[1]:
                    user = Users.get_by_id(int(user_id))
                    self.render_newpost()
            else:
                self.redirect('/')


        def post(self):
            title = self.request.get("title")
            content = self.request.get("content")
            image = self.request.get("file")
    
            if title and content:
                p = Posts(title = title, content = content)
                p.image=db.Blob(image)
                p.put()
                self.redirect("/")
            else:
                error = "Enter both title and text"
                self.render_newpost(title, content, error)

Here is my front page render class:

    class Main(Handler):
        def get(self):
            posts = db.GqlQuery("SELECT * FROM Posts Order by created DESC LIMIT 10")
            user_cookie = self.request.cookies.get('user')
            if user_cookie:
                user_id = user_cookie.split('|')[0]
                if hash_str(user_id) == user_cookie.split('|')[1]:
                    user = Users.get_by_id(int(user_id))
                    self.render("front.html", posts = posts, user=user)
            else:
                self.response.headers['Content-Type'] = "image/jpeg"
                self.render("front.html", posts = posts)
form to enter data:

         <form method="post" enctype="multipart/form-data">
            <div class="newpost">
                <label>Image:</label>
                <input type="file" name="file"/>
                <div class="label">Title: 
                    <input type="text" name="title" value="{{title}}"/>
                </div>
               <hr> 
                <div class="label">Content:
                    <textarea name="content">{{content}}</textarea>
                </div>
            </div>
            <input type="submit"/>
            <div class="error">{{error}}</div>
        </form>


and here is my home page template: **(The problem appears here!)**

                {% for post in posts %}
                    {% if post.image %}
                    <li>{{post.image}}
                    {% endif %}
                        <h4><a href="#">{{post.title}}</a></h4>
                        <p class="zoom">{{post.content}}</p>
                {% endfor %}

App successfully stores image, but when it returns to the front page trying to render image it gives this error: 

 **File "/home/wanhrust/google_appengine/newsite/templates/front.html", line 54, in top-level template code
    <li>{{post.image}}
UnicodeDecodeError: 'ascii' codec can't decode byte 0xff in position 0: ordinal not in range(128)**

I've been googling for several hours but without results. Any help?