title: Post a link to Facebook including an UIImage
body: <p>I want to post a link including an image to Facebook timeline:</p>
  
  <pre><code>UIImage *img = [UIImage imageNamed:@"1.png"];
      self.postParams =
      [[NSMutableDictionary alloc] initWithObjectsAndKeys:
       @"Here we go", @"message",
       @"https://developers.facebook.com/ios", @"link",
       UIImagePNGRepresentation(img), @"picture",
       @"Facebook SDK for iOS", @"name",
       @"Build great social apps and get more installs.", @"caption",
       @"The Facebook SDK for iOS makes it easier and faster to develop Facebook integrated iOS apps.", @"description",
       nil];
  
      [FBRequestConnection startWithGraphPath:@"me/feed" parameters:self.postParams HTTPMethod:@"POST"
                            completionHandler:^(FBRequestConnection *connection, id result, NSError *error) {
                                [self showAlert:@"Link is posted" result:result error:error];
      }];
  </code></pre>
  
  <p>The UIImage does not posted. Can you help me?</p>
  
  <p>But simply if I use :</p>
  
  <pre><code>@"https://developers.facebook.com/attachment/iossdk_logo.png", @"picture"
  </code></pre>
  
  <p>it works.</p>