docs: public static <T extends ImageGray<T>>
  	DescribeRegionPoint<T,TupleDesc_F64> sift( @Nullable ConfigSiftScaleSpace configSS,
  											   @Nullable ConfigSiftDescribe configDescribe, Class<T> imageType)
  	{
  		if( configSS == null )
  			configSS = new ConfigSiftScaleSpace();
  		configSS.checkValidity();
  
  		SiftScaleSpace ss = new SiftScaleSpace(configSS.firstOctave, configSS.lastOctave, configSS.numScales,
  				configSS.sigma0);
  
  		DescribePointSift<GrayF32> alg = FactoryDescribePointAlgs.sift(configDescribe,GrayF32.class);
  
  		return new DescribeRegionPoint_SIFT<>(ss, alg, imageType);
  	}