code: public static void hessianThree(GrayF32 inputDerivX , GrayF32 inputDerivY,
  									GrayF32 derivXX, GrayF32 derivYY, GrayF32 derivXY ,
  									ImageBorder_F32 border ) {
  		InputSanityCheck.reshapeOneIn(inputDerivX, inputDerivY, derivXX, derivYY, derivXY);
  
  		GradientThree.process(inputDerivX,derivXX,derivXY,border);
  
  		if( border != null )
  			ConvolveImage.vertical(GradientThree.kernelDeriv_F32,inputDerivY,derivYY,
  					new ImageBorder1D_F32(BorderIndex1D_Extend.class));
  		else
  			ConvolveImageNoBorder.vertical(GradientThree.kernelDeriv_F32,inputDerivY,derivYY);
  	}
docs: Computes the hessian given an image's gradient using a three derivative operator.
  
  @param inputDerivX Already computed image x-derivative.
  @param inputDerivY Already computed image y-derivative.
  @param derivXX Output second XX partial derivative.
  @param derivYY Output second YY partial derivative.
  @param derivXY Output second XY partial derivative.
  @param border Specifies how the image border is handled. If null the border is not processed.