title: captureStillImageAsynchronouslyFromConnection without JPG intermediary
body: <p>I'm trying to get as good an image as possible from the camera, but can only find examples that <code>captureStillImageAsynchronouslyFromConnection</code> and then go straight to:</p>
  
  <pre><code>NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];    
  UIImage *image = [[UIImage alloc] initWithData:imageData];
  </code></pre>
  
  <p>JPEG being lossy and all, is there any way to get the data as PNG, or even just RGBA (BGRA, what-have-you?). AVCaptureStillImageOutput doesn't seem to have any other NSData* methods....</p>
  
  <p>Actually looking at the CMSampleBufferRef, it seems like it's already locked as JPEG ~</p>
  
  <pre><code>formatDescription = &lt;CMVideoFormatDescription 0xfe5e1f0 [0x3e5ac650]&gt; {
  mediaType:'vide' 
  mediaSubType:'jpeg' 
  mediaSpecific: {
      codecType: 'jpeg'       dimensions: 2592 x 1936 
  } 
  extensions: {(null)}
  }
  </code></pre>
  
  <p>Is there some other way to take a full-res picture and get the raw data?</p>