title: How to send UIImage in JSON format, by filling a NSDictionary
body: <p>I'm trying to send data to a server with JSON. 
  I am able to create my NSDictionary with my objects and key parameters. 
  But I want to send my picture, and the picture is UIImage.</p>
  
  <pre><code> NSDictionary* mainJSON = [NSDictionary dictionaryWithObjectsAndKeys:
                            @"John",
                            @"First_Name",
                            @"McCintosh",
                            @"Last_name",
                            &lt;HERE I WANT PICTURE&gt;,
                            @"Profile_picture",
                            nil];
  
   // Here I convert to NSDATA 
   NSData * jsonData = [NSJSONSerialization dataWithJSONObject:mainJSON options:NSJSONWritingPrettyPrinted error:&amp;error];
  
   // Sending operation :
   dispatch_async(kBgQueue, ^
                     {
                         NSData * data = [NSData dataWithContentsOfURL:@"addresSERVER"];
                         [self performSelectorOnMainThread:@selector(receivedResponseFromServer:)
                                                withObject:data
                                             waitUntilDone:YES];
                     }
                     );
  </code></pre>
  
  <p>So I'm wondering how can I add my picture in my NSDictionary? 
  Because I want to send the content of my picture. If I add my object UIImage... I'll send the whole object right?</p>
  
  <p>Thanks</p>