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 * Image processing operations for SciJava Ops.
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package org.scijava.ops.image.filter.dog;

import java.util.function.Function;

import net.imglib2.RandomAccessible;
import net.imglib2.RandomAccessibleInterval;
import net.imglib2.type.NativeType;
import net.imglib2.type.numeric.NumericType;
import net.imglib2.view.IntervalView;
import net.imglib2.view.Views;

import org.scijava.function.Computers;
import org.scijava.ops.spi.OpDependency;

/**
 * Low-level difference of Gaussians (DoG) implementation which leans on other
 * ops to do the work.
 *
 * @author Christian Dietz (University of Konstanz)
 * @author Curtis Rueden
 * @param <T>
 * @implNote op names='filter.dog'
 */
public class DefaultDoG<T extends NumericType<T> & NativeType<T>> implements
	Computers.Arity3<RandomAccessibleInterval<T>, Computers.Arity1<RandomAccessibleInterval<T>, RandomAccessibleInterval<T>>, Computers.Arity1<RandomAccessibleInterval<T>, RandomAccessibleInterval<T>>, RandomAccessibleInterval<T>>
{

	@OpDependency(name = "create.img")
	private Function<RandomAccessibleInterval<T>, RandomAccessibleInterval<T>> tmpCreator;

	@OpDependency(name = "math.subtract")
	private Computers.Arity2<RandomAccessibleInterval<T>, RandomAccessibleInterval<T>, RandomAccessibleInterval<T>> subtracter;

	/**
	 * TODO
	 *
	 * @param input
	 * @param gauss1
	 * @param gauss2
	 * @param output
	 */
	@Override
	public void compute(final RandomAccessibleInterval<T> input,
		final Computers.Arity1<RandomAccessibleInterval<T>, RandomAccessibleInterval<T>> gauss1,
		final Computers.Arity1<RandomAccessibleInterval<T>, RandomAccessibleInterval<T>> gauss2,
		final RandomAccessibleInterval<T> output)
	{
		// input may potentially be translated
		final var translation = new long[input.numDimensions()];
		input.min(translation);

		final var tmpInterval = Views.interval(Views.translate(
			(RandomAccessible<T>) tmpCreator.apply(input), translation), output);

		gauss1.compute(input, tmpInterval);
		gauss2.compute(input, output);

		// TODO: is this safe?
		subtracter.compute(output, tmpInterval, output);
	}

}
