maxfilterbox.java

	public static < T extends Type< T > & Comparable< T > >
	void maxFilterBox(
			final RandomAccessibleInterval< T > input,
			final RandomAccessibleInterval< T > output,
			final ImgFactory< T > imgFactory, final T type,
			final int span )
	{
		final int n = input.numDimensions();

		final long[][] tmpdims = new long[ n ][];
		final long[][] tmpoffsets = new long[ n ][];
		tmpdims[ n - 1 ] = new long[ n ];
		tmpoffsets[ n - 1 ] = new long[ n ];
		output.dimensions( tmpdims[ n - 1 ] );
		output.min( tmpoffsets[ n - 1 ] );
		for ( int d = n - 2; d >= 0; --d )
		{
			tmpdims[ d ] = tmpdims[ d + 1 ].clone();
			tmpdims[ d ][ d + 1 ] += 2 * span;
			tmpoffsets[ d ] = tmpoffsets[ d + 1 ].clone();
			tmpoffsets[ d ][ d + 1 ] -= span;
		}

		RandomAccessibleInterval< T > currentOutput = null;
		final long[] spanMin = new long[ n ];
		final long[] spanMax = new long[ n ];
		for ( int d = 0; d < n; ++d )
		{
			Arrays.fill( spanMin, 0 );
			Arrays.fill( spanMax, 0 );
			spanMin[ d ] = -span;
			spanMax[ d ] = span;
			final FinalInterval spanInterval = new FinalInterval( spanMin, spanMax );

			final RandomAccessibleInterval< T > currentInput = ( d == 0 ) ? input : currentOutput;
			currentOutput = ( d == n - 1 ) ? output : Views.interval( Views.translate( imgFactory.create( tmpdims[ d ], type ), tmpoffsets[ d ] ), output );

			final NeighborhoodsIterableInterval< T > neighborhoods = new RectangleShape.NeighborhoodsIterableInterval<>( currentInput, spanInterval, RectangleNeighborhoodUnsafe.< T >factory() );
			final RandomAccess< T > out = currentOutput.randomAccess();
			for ( final Neighborhood< T > neighborhood : neighborhoods )
			{
				out.setPosition( neighborhood );
				final T o = out.get();
				o.set( neighborhood.firstElement() );
				for ( final T i : neighborhood )
					if ( i.compareTo( o ) > 0 )
						o.set( i );
			}
		}
	}