docs: public static <I extends ImageGray<I>, D extends ImageGray<D>>
  	DetectLineHoughPolar<I,D> houghPolar(ConfigHoughPolar config ,
  										 Class<I> imageType ,
  										 Class<D> derivType ) {
  
  		if( config == null )
  			throw new IllegalArgumentException("This is no default since minCounts must be specified");
  
  		ImageGradient<I,D> gradient = FactoryDerivative.sobel(imageType,derivType);
  
  		return new DetectLineHoughPolar<>(config.localMaxRadius, config.minCounts, config.resolutionRange,
  				config.resolutionAngle, config.thresholdEdge, config.maxLines, gradient);
  	}