code: public static <I extends ImageGray<I>, D extends ImageGray<D>>
  	GeneralFeatureIntensity<I,D>  fast( int pixelTol, int minCont, Class<I> imageType ) {
  		FastCornerDetector<I> alg =  FactoryIntensityPointAlg.fast(pixelTol, minCont, imageType);
  		return new WrapperFastCornerIntensity<>(alg);
  	}
docs: Feature intensity for Fast corner detector.  See {@link FastCornerDetector} for more details.
  
  @param pixelTol How different pixels need to be to be considered part of a corner. Image dependent.  Try 20 to start.
  @param minCont Minimum number of continue pixels in a circle for it ot be a corner.  Can be 9,10,11 or 12.
  @param imageType Type of input image it is computed form.
  @param <I> Input image type.
  @param <D> Derivative type.
  @return Fast feature intensity