/*
 * #%L
 * ImageJ software for multidimensional image processing and analysis.
 * %%
 * Copyright (C) 2014 - 2017 Board of Regents of the University of
 * Wisconsin-Madison, University of Konstanz and Brian Northan.
 * %%
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
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 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
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package net.imagej.ops.imagemoments.hu;

import net.imagej.ops.Op;
import net.imagej.ops.Ops;
import net.imagej.ops.imagemoments.AbstractImageMomentOp;
import net.imagej.ops.special.chain.RTs;
import net.imagej.ops.special.function.UnaryFunctionOp;
import net.imglib2.IterableInterval;
import net.imglib2.type.numeric.RealType;

import org.scijava.plugin.Plugin;

/**
 * {@link Op} to calculate the {@code imageMoments.huMoment2}.
 * 
 * @author Daniel Seebacher (University of Konstanz)
 * @author Christian Dietz (University of Konstanz)
 * @param <I> input type
 * @param <O> output type
 */
@Plugin(type = Ops.ImageMoments.HuMoment2.class, label = "Image Moment: HuMoment2")
public class DefaultHuMoment2<I extends RealType<I>, O extends RealType<O>>
	extends AbstractImageMomentOp<I, O> implements Ops.ImageMoments.HuMoment2
{

	private UnaryFunctionOp<IterableInterval<I>, O> normalizedCentralMoment20Func;

	private UnaryFunctionOp<IterableInterval<I>, O> normalizedCentralMoment02Func;

	private UnaryFunctionOp<IterableInterval<I>, O> normalizedCentralMoment11Func;

	@Override
	public void initialize() {
		normalizedCentralMoment11Func =
			RTs.function(ops(), Ops.ImageMoments.NormalizedCentralMoment11.class, in());
		normalizedCentralMoment20Func =
			RTs.function(ops(), Ops.ImageMoments.NormalizedCentralMoment20.class, in());
		normalizedCentralMoment02Func =
			RTs.function(ops(), Ops.ImageMoments.NormalizedCentralMoment02.class, in());
	}

	@Override
	public void compute(final IterableInterval<I> input, final O output) {

		double n11 = normalizedCentralMoment11Func.calculate(input).getRealDouble();
		double n20 = normalizedCentralMoment20Func.calculate(input).getRealDouble();
		double n02 = normalizedCentralMoment02Func.calculate(input).getRealDouble();

		output.setReal(Math.pow(n20 - n02, 2) - 4 * (Math.pow(n11, 2)));
	}
}

@@ -3357,17 +3357,17 @@
 n02, 2) 
--
++
  4 * (Ma

Fix sign in calculation of HuMoment2