swift 4. further enhancement

[burkaslarry]

There has a completion handler on AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation and stated as
// completion(image!, self.biggestRectangle(SobrCameraView.highAccuracyRectangleDetector?.features(in: enhancedImage) as! [CIRectangleFeature]))
When it goes to be rewritten as
func capture(_ captureOutput: AVCapturePhotoOutput, didFinishProcessingPhotoSampleBuffer photoSampleBuffer: CMSampleBuffer?, previewPhotoSampleBuffer: CMSampleBuffer?, resolvedSettings: AVCaptureResolvedPhotoSettings, bracketSettings: AVCaptureBracketedStillImageSettings?, error: NSError?) {

How can the completion handler be created instead ?

..

[burkaslarry]

As going on writing completion handler , it is quite clumsy and generating error about expecting type before ->

captureImage ( (image: image! as UIImage, feature: self.biggestRectangle(SobrCameraView.highAccuracyRectangleDetector?.features(in: enhancedImage) as! [CIRectangleFeature])) -> () )