code: static public <D extends ImageGray<D>>
  	void intensityE( D derivX , D derivY , GrayF32 intensity )
  	{
  		if( derivX instanceof GrayF32) {
  			GradientToEdgeFeatures.intensityE((GrayF32)derivX,(GrayF32)derivY,intensity);
  		} else if( derivX instanceof GrayS16) {
  			GradientToEdgeFeatures.intensityE((GrayS16)derivX,(GrayS16)derivY,intensity);
  		} else if( derivX instanceof GrayS32) {
  			GradientToEdgeFeatures.intensityE((GrayS32)derivX,(GrayS32)derivY,intensity);
  		} else {
  			throw new IllegalArgumentException("Unknown input type");
  		}
  	}
docs: Computes the edge intensity using a Euclidean norm.
  
  @param derivX Derivative along x-axis. Not modified.
  @param derivY Derivative along y-axis. Not modified.
  @param intensity Edge intensity.