code: public static <I extends ImageGray<I>, D extends ImageGray<D>, Desc extends TupleDesc>
  	PointTracker<I> combined(DetectDescribePoint<I, Desc> detector,
  							 AssociateDescription<Desc> associate,
  							 PkltConfig kltConfig ,
  							 int reactivateThreshold, Class<I> imageType )
  	{
  		Class<D> derivType = GImageDerivativeOps.getDerivativeType(imageType);
  
  		if( kltConfig == null ) {
  			kltConfig = new PkltConfig();
  		}
  
  		CombinedTrackerScalePoint<I, D,Desc> tracker =
  				FactoryTrackerAlg.combined(detector,associate, kltConfig,imageType,derivType);
  
  		return new PointTrackerCombined<>(tracker, reactivateThreshold, imageType, derivType);
  	}
docs: Creates a tracker that is a hybrid between KLT and Detect-Describe-Associate (DDA) trackers.
  
  @see CombinedTrackerScalePoint
  
  @param detector Feature detector and describer.
  @param associate Association algorithm.
  @param kltConfig Configuration for KLT tracker
  @param reactivateThreshold Tracks are reactivated after this many have been dropped.  Try 10% of maxMatches
  @param imageType Input image type.     @return Feature tracker