diff --git a/src/main/java/net/imglib2/algorithm/region/CircleCursor.java b/src/main/java/net/imglib2/algorithm/region/CircleCursor.java
new file mode 100644
index 000000000..558bd496b
--- /dev/null
+++ b/src/main/java/net/imglib2/algorithm/region/CircleCursor.java
@@ -0,0 +1,335 @@
+package net.imglib2.algorithm.region;
+
+import net.imglib2.Cursor;
+import net.imglib2.FinalInterval;
+import net.imglib2.Interval;
+import net.imglib2.Localizable;
+import net.imglib2.RandomAccess;
+import net.imglib2.RandomAccessible;
+import net.imglib2.Sampler;
+
+/**
+ * Iterates over a Bresenham 2D circle using the mid-point algorithm.
+ * <p>
+ * Each point of the circle is iterated exactly once, and there is no "hole" in
+ * the circle. Contrary to the algorithm linked below, the circles generated by
+ * this cursor are "slim": each pixel of the circle is connected with
+ * 8-connectivity. For instance, a bitmap excerpt from such a circle looks like
+ * this:
+ * 
+ * <pre>
+ * ..........
+ * OOO.......
+ * ...OO.....
+ * .....O....
+ * .....O....
+ * </pre>
+ * 
+ * @author Jean-Yves Tinevez
+ * @see <a href=
+ *      "https://en.wikipedia.org/wiki/Midpoint_circle_algorithm">Midpoint
+ *      circle algorithm on Wikipedia.</a>
+ *
+ */
+public class CircleCursor< T > implements Cursor< T >
+{
+	private final RandomAccessible< T > rai;
+
+	private final RandomAccess< T > ra;
+
+	private final Localizable center;
+
+	private final long radius;
+
+	private final int dimX;
+
+	private final int dimY;
+
+	private long x;
+
+	private long y;
+
+	private long dx;
+
+	private long dy;
+
+	private long f;
+
+	private Octant octant;
+
+	private boolean hasNext;
+
+	private static enum Octant
+	{
+		INIT, EAST, NORTH, WEST, SOUTH, O1, O2, O3, O4, O5, O6, O7, O8;
+	}
+
+	/**
+	 * Iterates over a Bresenham circle in the target {@link RandomAccessible}.
+	 * Each point of the circle is iterated exactly once, and there is no "hole"
+	 * in the circle.
+	 * 
+	 * @param rai
+	 *            the random accessible. It is the caller responsibility to
+	 *            ensure it can be accessed everywhere the circle will be
+	 *            iterated.
+	 * @param center
+	 *            the circle center. Must be at least of dimension 2. Dimensions
+	 *            0 and 1 are used to specify the circle center.
+	 * @param radius
+	 *            the circle radius. The circle is written in a plane in
+	 *            dimensions 0 and 1.
+	 */
+	public CircleCursor( final RandomAccessible< T > rai, final Localizable center, final long radius )
+	{
+		this( rai, center, radius, 0, 1 );
+	}
+
+	/**
+	 * Iterates over a Bresenham circle in the target {@link RandomAccessible}.
+	 * Each point of the circle is iterated exactly once, and there is no "hole"
+	 * in the circle.
+	 * 
+	 * @param rai
+	 *            the random accessible. It is the caller responsibility to
+	 *            ensure it can be accessed everywhere the circle will be
+	 *            iterated.
+	 * @param center
+	 *            the circle center. Must at least contain dimensions specified
+	 *            <code>dimX</code> and <code>dimY</code>.
+	 * @param radius
+	 *            the circle radius.
+	 * @param dimX
+	 *            the first dimension of the plane in which to draw the circle.
+	 * @param dimY
+	 *            the second dimension of the plane in which to draw the circle.
+	 */
+	public CircleCursor( final RandomAccessible< T > rai, final Localizable center, final long radius, final int dimX, final int dimY )
+	{
+		this.rai = rai;
+		this.center = center;
+		this.radius = radius;
+		this.dimX = dimX;
+		this.dimY = dimY;
+		// Make an interval to signal where we will access data.
+		final int numDimensions = rai.numDimensions();
+		final long[] minmax = new long[ 2 * numDimensions ];
+		for ( int d = 0; d < numDimensions; d++ )
+		{
+			if ( d == dimX || d == dimY )
+				minmax[ d ] = center.getLongPosition( d ) - radius;
+			else
+				minmax[ d ] = center.getLongPosition( d );
+		}
+		for ( int d = 0; d < numDimensions; d++ )
+		{
+			if ( d == dimX || d == dimY )
+				minmax[ d + numDimensions ] = center.getLongPosition( d ) + radius;
+			else
+				minmax[ d + numDimensions ] = center.getLongPosition( d );
+		}
+		final Interval interval = FinalInterval.createMinMax( minmax );
+		this.ra = rai.randomAccess( interval );
+		reset();
+	}
+
+	@Override
+	public void reset()
+	{
+		x = 0;
+		y = radius;
+		f = 1 - radius;
+		dx = 1;
+		dy = -2 * radius;
+		octant = Octant.INIT;
+		ra.setPosition( center );
+		hasNext = true;
+	}
+
+	@Override
+	public void fwd()
+	{
+		switch ( octant )
+		{
+		default:
+		case INIT:
+			ra.setPosition( center.getLongPosition( dimY ) + radius, dimY );
+			octant = Octant.NORTH;
+			break;
+
+		case NORTH:
+			ra.setPosition( center.getLongPosition( dimY ) - radius, dimY );
+			octant = Octant.SOUTH;
+			break;
+
+		case SOUTH:
+			ra.setPosition( center.getLongPosition( dimX ) - radius, dimX );
+			ra.setPosition( center.getLongPosition( dimY ), dimY );
+			octant = Octant.WEST;
+			break;
+
+		case WEST:
+			ra.setPosition( center.getLongPosition( dimX ) + radius, dimX );
+			octant = Octant.EAST;
+			break;
+
+		case EAST:
+			x = x + 1;
+			dx = dx + 2;
+			f = f + dx;
+			ra.setPosition( center.getLongPosition( dimX ) + x, dimX );
+			ra.setPosition( center.getLongPosition( dimY ) + y, dimY );
+			octant = Octant.O1;
+			break;
+
+		case O1:
+			ra.setPosition( center.getLongPosition( dimX ) - x, dimX );
+			octant = Octant.O2;
+			break;
+
+		case O2:
+			ra.setPosition( center.getLongPosition( dimY ) - y, dimY );
+			octant = Octant.O3;
+			break;
+
+		case O3:
+			ra.setPosition( center.getLongPosition( dimX ) + x, dimX );
+			octant = Octant.O4;
+			// Stop here if x==y, lest the 45º will be iterated twice.
+			if ( x >= y )
+				hasNext = false;
+			break;
+
+		case O4:
+			ra.setPosition( center.getLongPosition( dimX ) + y, dimX );
+			ra.setPosition( center.getLongPosition( dimY ) - x, dimY );
+			octant = Octant.O5;
+			break;
+
+		case O5:
+			ra.setPosition( center.getLongPosition( dimX ) - y, dimX );
+			octant = Octant.O6;
+			break;
+
+		case O6:
+			ra.setPosition( center.getLongPosition( dimY ) + x, dimY );
+			octant = Octant.O7;
+			break;
+
+		case O7:
+			ra.setPosition( center.getLongPosition( dimX ) + y, dimX );
+			octant = Octant.O8;
+			// Stop here if dx would cross y.
+			if ( x >= y - 1 )
+				hasNext = false;
+			break;
+
+		case O8:
+			if ( f > 0 )
+			{
+				y = y - 1;
+				dy = dy + 2;
+				f = f + dy;
+			}
+			x = x + 1;
+			dx = dx + 2;
+			f = f + dx;
+			ra.setPosition( center.getLongPosition( dimX ) + x, dimX );
+			ra.setPosition( center.getLongPosition( dimY ) + y, dimY );
+			octant = Octant.O1;
+			break;
+		}
+	}
+
+	@Override
+	public boolean hasNext()
+	{
+		return hasNext;
+	}
+
+	@Override
+	public void localize( final float[] position )
+	{
+		ra.localize( position );
+	}
+
+	@Override
+	public void localize( final double[] position )
+	{
+		ra.localize( position );
+	}
+
+	@Override
+	public float getFloatPosition( final int d )
+	{
+		return ra.getFloatPosition( d );
+	}
+
+	@Override
+	public double getDoublePosition( final int d )
+	{
+		return ra.getDoublePosition( d );
+	}
+
+	@Override
+	public int numDimensions()
+	{
+		return ra.numDimensions();
+	}
+
+	@Override
+	public T get()
+	{
+		return ra.get();
+	}
+
+	@Override
+	public Sampler< T > copy()
+	{
+		return ra.copy();
+	}
+
+	@Override
+	public void jumpFwd( final long steps )
+	{
+		for ( int i = 0; i < steps; i++ )
+			fwd();
+	}
+
+	@Override
+	public T next()
+	{
+		fwd();
+		return get();
+	}
+
+	@Override
+	public void localize( final int[] position )
+	{
+		ra.localize( position );
+	}
+
+	@Override
+	public void localize( final long[] position )
+	{
+		ra.localize( position );
+	}
+
+	@Override
+	public int getIntPosition( final int d )
+	{
+		return ra.getIntPosition( d );
+	}
+
+	@Override
+	public long getLongPosition( final int d )
+	{
+		return ra.getLongPosition( d );
+	}
+
+	@Override
+	public Cursor< T > copyCursor()
+	{
+		return new CircleCursor<>( rai, center, radius, dimX, dimY );
+	}
+}
diff --git a/src/main/java/net/imglib2/algorithm/region/Circles.java b/src/main/java/net/imglib2/algorithm/region/Circles.java
new file mode 100644
index 000000000..b00d59b43
--- /dev/null
+++ b/src/main/java/net/imglib2/algorithm/region/Circles.java
@@ -0,0 +1,193 @@
+package net.imglib2.algorithm.region;
+
+import net.imglib2.Cursor;
+import net.imglib2.Localizable;
+import net.imglib2.RandomAccessible;
+import net.imglib2.type.Type;
+import net.imglib2.type.numeric.RealType;
+import net.imglib2.type.operators.Add;
+
+/**
+ * Write circles in an image using the midpoint algorithm.
+ * 
+ * @author Jean-Yves Tinevez
+ * @see <a href=
+ *      "https://en.wikipedia.org/wiki/Midpoint_circle_algorithm">Midpoint
+ *      circle algorithm on Wikipedia.</a>
+ * @see CircleCursor {@link CircleCursor}
+ */
+public class Circles
+{
+
+	/**
+	 * Writes a circle in the target {@link RandomAccessible}. The circle is
+	 * written by <b>incrementing</b> the pixel values by 1 along the circle.
+	 * The circle is written in a plane in dimensions 0 and 1.
+	 * 
+	 * @param rai
+	 *            the random accessible. It is the caller responsibility to
+	 *            ensure it can be accessed everywhere the circle will be
+	 *            iterated.
+	 * @param center
+	 *            the circle center. Must be at least of dimension 2. Dimensions
+	 *            0 and 1 are used to specify the circle center.
+	 * @param radius
+	 *            the circle radius.
+	 * @param <T>
+	 *            the type of the target image.
+	 */
+	public static < T extends RealType< T > > void inc( final RandomAccessible< T > rai, final Localizable center, final long radius )
+	{
+		inc( rai, center, radius, 0, 1 );
+	}
+
+	/**
+	 * Writes a circle in the target {@link RandomAccessible}. The circle is
+	 * written by <b>incrementing</b> the pixel values by 1 along the circle.
+	 * 
+	 * @param rai
+	 *            the random accessible. It is the caller responsibility to
+	 *            ensure it can be accessed everywhere the circle will be
+	 *            iterated.
+	 * @param center
+	 *            the circle center. Must contain at least of dimensions
+	 *            <code>dimX</code> and <code>dimY</code>, used to specify the
+	 *            circle center.
+	 * @param radius
+	 *            the circle radius.
+	 * @param dimX
+	 *            the first dimension of the plane in which to draw the circle.
+	 * @param dimY
+	 *            the second dimension of the plane in which to draw the circle.
+	 * @param <T>
+	 *            the type of the target image.
+	 */
+	public static < T extends RealType< T > > void inc( final RandomAccessible< T > rai, final Localizable center,
+			final long radius, final int dimX, final int dimY )
+	{
+		final Cursor< T > cursor = new CircleCursor< T >( rai, center, radius, dimX, dimY );
+		while ( cursor.hasNext() )
+		{
+			cursor.fwd();
+			cursor.get().inc();
+		}
+	}
+
+	/**
+	 * Writes a circle in the target {@link RandomAccessible}. The circle is
+	 * written by <b>setting</b> the pixel values with the specified value. The
+	 * circle is written in a plane in dimensions 0 and 1.
+	 * 
+	 * @param rai
+	 *            the target random accessible. It is the caller responsibility
+	 *            to ensure it can be accessed everywhere the circle will be
+	 *            iterated.
+	 * @param center
+	 *            the circle center. Must be at least of dimension 2. Dimensions
+	 *            0 and 1 are used to specify the circle center.
+	 * @param radius
+	 *            the circle radius.
+	 * @param value
+	 *            the value to write along the circle.
+	 * @param <T>
+	 *            the type of the target image.
+	 */
+	public static < T extends Type< T > > void set( final RandomAccessible< T > rai, final Localizable center, final long radius, final T value )
+	{
+		set( rai, center, radius, 0, 1, value );
+	}
+
+	/**
+	 * Writes a circle in the target {@link RandomAccessible}. The circle is
+	 * written by <b>setting</b> the pixel values with the specified value.
+	 * 
+	 * @param rai
+	 *            the target random accessible. It is the caller responsibility
+	 *            to ensure it can be accessed everywhere the circle will be
+	 *            iterated.
+	 * @param center
+	 *            the circle center. Must contain at least of dimensions
+	 *            <code>dimX</code> and <code>dimY</code>, used to specify the
+	 *            circle center.
+	 * @param radius
+	 *            the circle radius.
+	 * @param dimX
+	 *            the first dimension of the plane in which to draw the circle.
+	 * @param dimY
+	 *            the second dimension of the plane in which to draw the circle.
+	 * @param value
+	 *            the value to write along the circle.
+	 * @param <T>
+	 *            the type of the target image.
+	 */
+	public static < T extends Type< T > > void set( final RandomAccessible< T > rai, final Localizable center, final long radius, final int dimX, final int dimY, final T value )
+	{
+		final Cursor< T > cursor = new CircleCursor< T >( rai, center, radius, dimX, dimY );
+		while ( cursor.hasNext() )
+		{
+			cursor.fwd();
+			cursor.get().set( value );
+		}
+	}
+	
+	/**
+	 * Writes a circle in the target {@link RandomAccessible}. The circle is
+	 * written by <b>adding</b> the specified value to the pixel values already
+	 * in the image. The circle is written in a plane in dimensions 0 and 1.
+	 * 
+	 * @param rai
+	 *            the random accessible. It is the caller responsibility to
+	 *            ensure it can be accessed everywhere the circle will be
+	 *            iterated.
+	 * @param center
+	 *            the circle center. Must be at least of dimension 2. Dimensions
+	 *            0 and 1 are used to specify the circle center.
+	 * @param radius
+	 *            the circle radius.
+	 * @param value
+	 *            the value to add along the circle.
+	 * @param <T>
+	 *            the type of the target image.
+	 */
+	public static < T extends Add< T > > void add( final RandomAccessible< T > rai, final Localizable center, final long radius, final T value )
+	{
+		add( rai, center, radius, 0, 1, value );
+	}
+
+	/**
+	 * Writes a circle in the target {@link RandomAccessible}. The circle is
+	 * written by <b>adding</b> the specified value to the pixel values already
+	 * in the image.
+	 * 
+	 * @param rai
+	 *            the random accessible. It is the caller responsibility to
+	 *            ensure it can be accessed everywhere the circle will be
+	 *            iterated.
+	 * @param center
+	 *            the circle center. Must contain at least of dimensions
+	 *            <code>dimX</code> and <code>dimY</code>, used to specify the
+	 *            circle center.
+	 * @param radius
+	 *            the circle radius.
+	 * @param dimX
+	 *            the first dimension of the plane in which to draw the circle.
+	 * @param dimY
+	 *            the second dimension of the plane in which to draw the circle.
+	 * @param value
+	 *            the value to add along the circle.
+	 * @param <T>
+	 *            the type of the target image.
+	 */
+	public static < T extends Add< T > > void add( final RandomAccessible< T > rai, final Localizable center, final long radius, final int dimX, final int dimY, final T value )
+	{
+		final Cursor< T > cursor = new CircleCursor< T >( rai, center, radius, dimX, dimY );
+		while ( cursor.hasNext() )
+		{
+			cursor.fwd();
+			cursor.get().add( value );
+		}
+	}
+	
+	private Circles()
+	{}
+}
diff --git a/src/main/java/net/imglib2/algorithm/region/EllipseCursor.java b/src/main/java/net/imglib2/algorithm/region/EllipseCursor.java
new file mode 100644
index 000000000..c75e322cf
--- /dev/null
+++ b/src/main/java/net/imglib2/algorithm/region/EllipseCursor.java
@@ -0,0 +1,423 @@
+package net.imglib2.algorithm.region;
+
+import net.imglib2.Cursor;
+import net.imglib2.FinalInterval;
+import net.imglib2.Interval;
+import net.imglib2.Localizable;
+import net.imglib2.RandomAccess;
+import net.imglib2.RandomAccessible;
+import net.imglib2.Sampler;
+import net.imglib2.util.Util;
+
+/**
+ * Iterates over a Bresenham 2D ellipse using the mid-point algorithm.
+ * <p>
+ * Each point of the ellipse is iterated exactly once, and there is no "hole" in
+ * the ellipse. A bitmap excerpt from such a ellipse looks like this:
+ * 
+ * <pre>
+ * ..........
+ * OOO.......
+ * ...OO.....
+ * .....O....
+ * .....O....
+ * </pre>
+ * <p>
+ * The circle generated with equal X and Y radii is not strictly equivalent to
+ * the circle generated by the {@link CircleCursor}.
+ * 
+ * @author Jean-Yves Tinevez
+ */
+public class EllipseCursor< T > implements Cursor< T >
+{
+	private final RandomAccessible< T > rai;
+
+	private final RandomAccess< T > ra;
+
+	private final Localizable center;
+
+	private final long radiusX;
+
+	private final long radiusY;
+
+	private final int dimX;
+
+	private final int dimY;
+
+	private long x;
+
+	private long y;
+
+	private double px;
+
+	private double py;
+
+	private double p;
+
+	private Octant octant;
+
+	private boolean hasNext;
+
+	private static enum Octant
+	{
+		INIT,
+		EAST, NORTH, WEST, SOUTH,
+		REGION1_Q1, REGION1_Q2, REGION1_Q3, REGION1_Q4,
+		REGION2_Q1, REGION2_Q2, REGION2_Q3, REGION2_Q4;
+	}
+
+	/**
+	 * Iterates over a Bresenham ellipse in the target {@link RandomAccessible}.
+	 * Each point of the ellipse is iterated exactly once, and there is no
+	 * "hole" in the ellipse. The ellipse is written in a plane in dimensions 0
+	 * and 1.
+	 * 
+	 * @param rai
+	 *            the random accessible. It is the caller responsibility to
+	 *            ensure it can be accessed everywhere the ellipse will be
+	 *            iterated.
+	 * @param center
+	 *            the ellipse center. Must be at least of dimension 2.
+	 *            Dimensions 0 and 1 are used to specify the ellipse center.
+	 * @param radiusX
+	 *            the ellipse radius in the dimension 0.
+	 * @param radiusY
+	 *            the ellipse radius in the dimension 1.
+	 */
+	public EllipseCursor( final RandomAccessible< T > rai, final Localizable center, final long radiusX, final long radiusY )
+	{
+		this( rai, center, radiusX, radiusY, 0, 1 );
+	}
+
+	/**
+	 * Iterates over a Bresenham ellipse in the target {@link RandomAccessible}.
+	 * Each point of the ellipse is iterated exactly once, and there is no
+	 * "hole" in the ellipse.
+	 * 
+	 * @param rai
+	 *            the random accessible. It is the caller responsibility to
+	 *            ensure it can be accessed everywhere the ellipse will be
+	 *            iterated.
+	 * @param center
+	 *            the ellipse center. Must be at least of dimension 2.
+	 *            Dimensions 0 and 1 are used to specify the ellipse center.
+	 * @param radiusX
+	 *            the ellipse radius in dimension X.
+	 * @param radiusY
+	 *            the ellipse radius in dimension Y.
+	 * @param dimX
+	 *            the first dimension of the plane in which to draw the ellipse.
+	 * @param dimY
+	 *            the second dimension of the plane in which to draw the
+	 *            ellipse.
+	 */
+	public EllipseCursor( final RandomAccessible< T > rai, final Localizable center, final long radiusX, final long radiusY, final int dimX, final int dimY )
+	{
+		this.rai = rai;
+		this.center = center;
+		if ( radiusX > radiusY )
+		{
+			// Swap X & Y if radiusX if larger than radiusY and avoid issues
+			// with slim ellipses.
+			this.radiusX = radiusY;
+			this.radiusY = radiusX;
+			this.dimX = dimY;
+			this.dimY = dimX;
+		}
+		else
+		{
+			this.radiusX = radiusX;
+			this.radiusY = radiusY;
+			this.dimX = dimX;
+			this.dimY = dimY;
+		}
+		// Make an interval to signal where we will access data.
+		final int numDimensions = rai.numDimensions();
+		final long[] minmax = new long[ 2 * numDimensions ];
+		for ( int d = 0; d < numDimensions; d++ )
+		{
+			if ( d == dimX )
+				minmax[ d ] = center.getLongPosition( d ) - radiusX;
+			else if ( d == dimY )
+				minmax[ d ] = center.getLongPosition( d ) - radiusY;
+			else
+				minmax[ d ] = center.getLongPosition( d );
+		}
+		for ( int d = 0; d < numDimensions; d++ )
+		{
+			if ( d == dimX )
+				minmax[ d + numDimensions ] = center.getLongPosition( d ) + radiusX;
+			else if ( d == dimY )
+				minmax[ d + numDimensions ] = center.getLongPosition( d ) + radiusY;
+			else
+				minmax[ d + numDimensions ] = center.getLongPosition( d );
+		}
+		final Interval interval = FinalInterval.createMinMax( minmax );
+		this.ra = rai.randomAccess( interval );
+		reset();
+	}
+
+	@Override
+	public void reset()
+	{
+		// Prepare for region 1.
+		x = 0l;
+		y = radiusY;
+		px = 0.;
+		py = 2. * radiusX * radiusX * y;
+		p = radiusY * radiusY - ( radiusX * radiusX * radiusY ) + ( 0.25 * radiusX * radiusX );
+
+		octant = Octant.INIT;
+		ra.setPosition( center );
+		hasNext = true;
+	}
+
+	@Override
+	public void fwd()
+	{
+		switch ( octant )
+		{
+		default:
+		case INIT:
+			ra.setPosition( center.getLongPosition( dimY ) + radiusY, dimY );
+			octant = Octant.NORTH;
+			break;
+
+		case NORTH:
+			ra.setPosition( center.getLongPosition( dimY ) - radiusY, dimY );
+			octant = Octant.SOUTH;
+			break;
+
+		case SOUTH:
+			ra.setPosition( center.getLongPosition( dimX ) - radiusX, dimX );
+			ra.setPosition( center.getLongPosition( dimY ), dimY );
+			octant = Octant.WEST;
+			break;
+
+		case WEST:
+			ra.setPosition( center.getLongPosition( dimX ) + radiusX, dimX );
+			octant = Octant.EAST;
+
+			// Special case: rx = ry = 1.
+			if ( radiusX == 1 && radiusY == 1 )
+				hasNext = false;
+
+			break;
+
+		case EAST:
+			// Move to region 1.
+			x++;
+			px += 2. * radiusY * radiusY;
+			if ( p < 0 )
+			{
+				p += ( radiusY * radiusY ) + px;
+			}
+			else
+			{
+				y--;
+				py -= 2 * ( radiusX * radiusX );
+				p += ( radiusY * radiusY ) + px - py;
+			}
+
+			ra.setPosition( center.getLongPosition( dimX ) + x, dimX );
+			ra.setPosition( center.getLongPosition( dimY ) + y, dimY );
+			octant = Octant.REGION1_Q1;
+			break;
+
+		case REGION1_Q1:
+			ra.setPosition( center.getLongPosition( dimX ) - x, dimX );
+			octant = Octant.REGION1_Q2;
+			break;
+
+		case REGION1_Q2:
+			ra.setPosition( center.getLongPosition( dimY ) - y, dimY );
+			octant = Octant.REGION1_Q3;
+			break;
+
+		case REGION1_Q3:
+			ra.setPosition( center.getLongPosition( dimX ) + x, dimX );
+			octant = Octant.REGION1_Q4;
+			
+			// Don't overwrite equator for small radii.
+			if ( y == 1 && x <= 2 )
+				hasNext = false;
+			
+			break;
+
+		case REGION1_Q4:
+
+			if ( px < py )
+			{
+				// Back to Q1 of Region 1.
+				x++;
+				px += 2. * radiusY * radiusY;
+				if ( p < 0 )
+				{
+					p += ( radiusY * radiusY ) + px;
+				}
+				else
+				{
+					y--;
+					py -= 2 * ( radiusX * radiusX );
+					p += ( radiusY * radiusY ) + px - py;
+				}
+
+				octant = Octant.REGION1_Q1;
+			}
+			else
+			{
+				// Maybe go to Region 2.
+				p = radiusY * radiusY * ( x + 0.5 ) * ( x + 0.5 ) + radiusX * radiusX * ( y - 1 ) * ( y - 1 ) - radiusX * radiusX * radiusY * radiusY;
+				y--;
+				py -= 2. * radiusX * radiusX;
+				if ( p > 0 )
+				{
+					p += radiusX * radiusX - py;
+				}
+				else
+				{
+					x++;
+					px += 2. * radiusY * radiusY;
+					p += radiusX * radiusX - py + px;
+				}
+				octant = Octant.REGION2_Q1;
+			}
+
+			ra.setPosition( center.getLongPosition( dimX ) + x, dimX );
+			ra.setPosition( center.getLongPosition( dimY ) + y, dimY );
+			break;
+
+		case REGION2_Q1:
+			ra.setPosition( center.getLongPosition( dimX ) - x, dimX );
+			octant = Octant.REGION2_Q2;
+			break;
+
+		case REGION2_Q2:
+			ra.setPosition( center.getLongPosition( dimY ) - y, dimY );
+			octant = Octant.REGION2_Q3;
+			break;
+
+		case REGION2_Q3:
+			ra.setPosition( center.getLongPosition( dimX ) + x, dimX );
+			octant = Octant.REGION2_Q4;
+			if ( y <= 1 )
+				hasNext = false;
+			break;
+
+		case REGION2_Q4:
+			y--;
+			py -= 2. * radiusX * radiusX;
+			if ( p > 0 )
+			{
+				p += radiusX * radiusX - py;
+			}
+			else
+			{
+				x++;
+				px += 2. * radiusY * radiusY;
+				p += radiusX * radiusX - py + px;
+			}
+			octant = Octant.REGION2_Q1;
+			ra.setPosition( center.getLongPosition( dimX ) + x, dimX );
+			ra.setPosition( center.getLongPosition( dimY ) + y, dimY );
+		}
+	}
+
+	@Override
+	public boolean hasNext()
+	{
+		return hasNext;
+	}
+
+	@Override
+	public void localize( final float[] position )
+	{
+		ra.localize( position );
+	}
+
+	@Override
+	public void localize( final double[] position )
+	{
+		ra.localize( position );
+	}
+
+	@Override
+	public float getFloatPosition( final int d )
+	{
+		return ra.getFloatPosition( d );
+	}
+
+	@Override
+	public double getDoublePosition( final int d )
+	{
+		return ra.getDoublePosition( d );
+	}
+
+	@Override
+	public int numDimensions()
+	{
+		return ra.numDimensions();
+	}
+
+	@Override
+	public T get()
+	{
+		return ra.get();
+	}
+
+	@Override
+	public Sampler< T > copy()
+	{
+		return ra.copy();
+	}
+
+	@Override
+	public void jumpFwd( final long steps )
+	{
+		for ( int i = 0; i < steps; i++ )
+			fwd();
+	}
+
+	@Override
+	public T next()
+	{
+		fwd();
+		return get();
+	}
+
+	@Override
+	public void localize( final int[] position )
+	{
+		ra.localize( position );
+	}
+
+	@Override
+	public void localize( final long[] position )
+	{
+		ra.localize( position );
+	}
+
+	@Override
+	public int getIntPosition( final int d )
+	{
+		return ra.getIntPosition( d );
+	}
+
+	@Override
+	public long getLongPosition( final int d )
+	{
+		return ra.getLongPosition( d );
+	}
+
+	@Override
+	public Cursor< T > copyCursor()
+	{
+		return new EllipseCursor<>( rai, center, radiusX, radiusY, dimX, dimY );
+	}
+
+	@Override
+	public String toString()
+	{
+		return super.toString() + " pos=" + Util.printCoordinates( this ) + ",\t" + octant + ",\tx = " + x + ",\ty = " + y;
+	}
+}
diff --git a/src/main/java/net/imglib2/algorithm/region/Ellipses.java b/src/main/java/net/imglib2/algorithm/region/Ellipses.java
new file mode 100644
index 000000000..8bc7968ca
--- /dev/null
+++ b/src/main/java/net/imglib2/algorithm/region/Ellipses.java
@@ -0,0 +1,209 @@
+package net.imglib2.algorithm.region;
+
+import net.imglib2.Cursor;
+import net.imglib2.Localizable;
+import net.imglib2.RandomAccessible;
+import net.imglib2.type.Type;
+import net.imglib2.type.numeric.RealType;
+import net.imglib2.type.operators.Add;
+
+/**
+ * Write ellipses in an image using the midpoint algorithm.
+ * 
+ * @author Jean-Yves Tinevez
+ * @see EllipseCursor {@link EllipseCursor}
+ * @see EllipseCursor {@link EllipseCursor}
+ */
+public class Ellipses
+{
+
+	/**
+	 * Writes an ellipse in the target {@link RandomAccessible}. The ellipse is
+	 * written by <b>incrementing</b> the pixel values by 1 along the ellipse.
+	 * The ellipse is written in a plane in dimensions 0 and 1.
+	 * 
+	 * @param rai
+	 *            the random accessible. It is the caller responsibility to
+	 *            ensure it can be accessed everywhere the ellipse will be
+	 *            iterated.
+	 * @param center
+	 *            the ellipse center. Must be at least of dimension 2.
+	 *            Dimensions 0 and 1 are used to specify the ellipse center.
+	 * @param radiusX
+	 *            the ellipse X radius.
+	 * @param radiusY
+	 *            the ellipse Y radius.
+	 * @param <T>
+	 *            the type of the target image.
+	 */
+	public static < T extends RealType< T > > void inc( final RandomAccessible< T > rai, final Localizable center, final long radiusX, final long radiusY )
+	{
+		inc( rai, center, radiusX, radiusY, 0, 1 );
+	}
+
+	/**
+	 * Writes an ellipse in the target {@link RandomAccessible}. The ellipse is
+	 * written by <b>incrementing</b> the pixel values by 1 along the ellipse.
+	 * The ellipse is written in a plane in specified dimensions.
+	 * 
+	 * @param rai
+	 *            the random accessible. It is the caller responsibility to
+	 *            ensure it can be accessed everywhere the ellipse will be
+	 *            iterated.
+	 * @param center
+	 *            the ellipse center. Must contain at least dimensions
+	 *            <code>dimX</code> and <code>dimY</code>, used to specify the
+	 *            ellipse center.
+	 * @param radiusX
+	 *            the ellipse X radius.
+	 * @param radiusY
+	 *            the ellipse Y radius.
+	 * @param dimX
+	 *            the first dimension of the plane in which to draw the ellipse.
+	 * @param dimY
+	 *            the second dimension of the plane in which to draw the
+	 *            ellipse.
+	 * @param <T>
+	 *            the type of the target image.
+	 */
+	public static < T extends RealType< T > > void inc( final RandomAccessible< T > rai, final Localizable center,
+			final long radiusX, final long radiusY, final int dimX, final int dimY )
+	{
+		final Cursor< T > cursor = new EllipseCursor< T >( rai, center, radiusX, radiusY, dimX, dimY );
+		while ( cursor.hasNext() )
+		{
+			cursor.fwd();
+			cursor.get().inc();
+		}
+	}
+
+	/**
+	 * Writes an ellipse in the target {@link RandomAccessible}. The ellipse is
+	 * written by <b>setting</b> the pixel values with the specified value. The
+	 * ellipse is written in a plane in dimensions 0 and 1.
+	 * 
+	 * @param rai
+	 *            the target random accessible. It is the caller responsibility
+	 *            to ensure it can be accessed everywhere the ellipse will be
+	 *            iterated.
+	 * @param center
+	 *            the ellipse center. Must be at least of dimension 2.
+	 *            Dimensions 0 and 1 are used to specify the ellipse center.
+	 * @param radiusX
+	 *            the ellipse X radius.
+	 * @param radiusY
+	 *            the ellipse Y radius.
+	 * @param value
+	 *            the value to write along the ellipse.
+	 * @param <T>
+	 *            the type of the target image.
+	 */
+	public static < T extends Type< T > > void set( final RandomAccessible< T > rai, final Localizable center, final long radiusX, final long radiusY, final T value )
+	{
+		set( rai, center, radiusX, radiusY, 0, 1, value );
+	}
+
+	/**
+	 * Writes an ellipse in the target {@link RandomAccessible}. The ellipse is
+	 * written by <b>setting</b> the pixel values with the specified value.
+	 * 
+	 * @param rai
+	 *            the target random accessible. It is the caller responsibility
+	 *            to ensure it can be accessed everywhere the ellipse will be
+	 *            iterated.
+	 * @param center
+	 *            the ellipse center. Must contain at least dimensions
+	 *            <code>dimX</code> and <code>dimY</code>, used to specify the
+	 *            ellipse center.
+	 * @param radiusX
+	 *            the ellipse X radius.
+	 * @param radiusY
+	 *            the ellipse Y radius.
+	 * @param dimX
+	 *            the first dimension of the plane in which to draw the ellipse.
+	 * @param dimY
+	 *            the second dimension of the plane in which to draw the
+	 *            ellipse.
+	 * @param value
+	 *            the value to write along the ellipse.
+	 * @param <T>
+	 *            the type of the target image.
+	 */
+	public static < T extends Type< T > > void set( final RandomAccessible< T > rai, final Localizable center,
+			final long radiusX, final long radiusY, final int dimX, final int dimY, final T value )
+	{
+		final Cursor< T > cursor = new EllipseCursor< T >( rai, center, radiusX, radiusY, dimX, dimY );
+		while ( cursor.hasNext() )
+		{
+			cursor.fwd();
+			cursor.get().set( value );
+		}
+	}
+	
+	/**
+	 * Writes an ellipse in the target {@link RandomAccessible}. The ellipse is
+	 * written by <b>adding</b> the specified value to the pixel values already
+	 * in the image. The ellipse is written in a plane in dimensions 0 and 1.
+	 * 
+	 * @param rai
+	 *            the random accessible. It is the caller responsibility to
+	 *            ensure it can be accessed everywhere the ellipse will be
+	 *            iterated.
+	 * @param center
+	 *            the ellipse center. Must be at least of dimension 2.
+	 *            Dimensions 0 and 1 are used to specify the ellipse center.
+	 * @param radiusX
+	 *            the ellipse X radius.
+	 * @param radiusY
+	 *            the ellipse Y radius.
+	 * @param value
+	 *            the value to add along the ellipse.
+	 * @param <T>
+	 *            the type of the target image.
+	 */
+	public static < T extends Add< T > > void add( final RandomAccessible< T > rai, final Localizable center, final long radiusX, final long radiusY, final T value )
+	{
+		add( rai, center, radiusX, radiusY, 0, 1, value );
+	}
+
+	/**
+	 * Writes an ellipse in the target {@link RandomAccessible}. The ellipse is
+	 * written by <b>adding</b> the specified value to the pixel values already
+	 * in the image.
+	 * 
+	 * @param rai
+	 *            the random accessible. It is the caller responsibility to
+	 *            ensure it can be accessed everywhere the ellipse will be
+	 *            iterated.
+	 * @param center
+	 *            the ellipse center. Must contain at least dimensions
+	 *            <code>dimX</code> and <code>dimY</code>, used to specify the
+	 *            ellipse center.
+	 * @param radiusX
+	 *            the ellipse X radius.
+	 * @param radiusY
+	 *            the ellipse Y radius.
+	 * @param dimX
+	 *            the first dimension of the plane in which to draw the ellipse.
+	 * @param dimY
+	 *            the second dimension of the plane in which to draw the
+	 *            ellipse.
+	 * @param value
+	 *            the value to add along the ellipse.
+	 * @param <T>
+	 *            the type of the target image.
+	 */
+	public static < T extends Add< T > > void add( final RandomAccessible< T > rai, final Localizable center,
+			final long radiusX, final long radiusY, final int dimX, final int dimY, final T value )
+	{
+		final Cursor< T > cursor = new EllipseCursor< T >( rai, center, radiusX, radiusY, dimX, dimY );
+		while ( cursor.hasNext() )
+		{
+			cursor.fwd();
+			cursor.get().add( value );
+		}
+	}
+	
+	private Ellipses()
+	{}
+}
diff --git a/src/test/java/net/imglib2/algorithm/region/CircleTest.java b/src/test/java/net/imglib2/algorithm/region/CircleTest.java
new file mode 100644
index 000000000..b3d713c4a
--- /dev/null
+++ b/src/test/java/net/imglib2/algorithm/region/CircleTest.java
@@ -0,0 +1,65 @@
+package net.imglib2.algorithm.region;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import net.imglib2.Point;
+import net.imglib2.img.array.ArrayImg;
+import net.imglib2.img.array.ArrayImgs;
+import net.imglib2.img.basictypeaccess.array.ShortArray;
+import net.imglib2.type.numeric.integer.UnsignedShortType;
+import net.imglib2.util.Util;
+
+public class CircleTest
+{
+
+	@Test
+	public void testIterateOnce()
+	{
+		final ArrayImg< UnsignedShortType, ShortArray > img = ArrayImgs.unsignedShorts( 512l, 512l );
+
+		final Point center = new Point( 255l, 255l );
+		for ( long r = 1l; r < 256l; r++ )
+		{
+			Circles.inc( img, center, r );
+			
+			final CircleCursor< UnsignedShortType > cursor = new CircleCursor<>( img, center, r );
+			while ( cursor.hasNext() )
+			{
+				cursor.fwd();
+				assertEquals( "Pixel at coordinates " + Util.printCoordinates( cursor ) + " has not been iterated one time.", 1, cursor.get().get() );
+			}
+		}
+	}
+
+	@Test
+	public void testDistanceToCenter()
+	{
+		final ArrayImg< UnsignedShortType, ShortArray > img = ArrayImgs.unsignedShorts( 512l, 512l );
+
+		final Point center = new Point( 255l, 255l );
+		final long[] pos = new long[ img.numDimensions() ];
+
+		for ( long r = 1l; r < 256l; r++ )
+		{
+			final CircleCursor< UnsignedShortType > cursor = new CircleCursor<>( img, center, r );
+			while ( cursor.hasNext() )
+			{
+				cursor.fwd();
+				cursor.localize( pos );
+
+				double d2 = 0.;
+				for ( int d = 0; d < img.numDimensions(); d++ )
+				{
+					final double dx = center.getDoublePosition( d ) - cursor.getDoublePosition( d );
+					d2 += dx * dx;
+				}
+				final double dist = Math.sqrt( d2 );
+
+				assertEquals( "Circle coordinates " + Util.printCoordinates( cursor ) + " is too far from expected radius " + r + ".",
+						r, dist, 0.5 );
+			}
+		}
+	}
+}
diff --git a/src/test/java/net/imglib2/algorithm/region/EllipseTest.java b/src/test/java/net/imglib2/algorithm/region/EllipseTest.java
new file mode 100644
index 000000000..cce38d30c
--- /dev/null
+++ b/src/test/java/net/imglib2/algorithm/region/EllipseTest.java
@@ -0,0 +1,73 @@
+package net.imglib2.algorithm.region;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import net.imglib2.Point;
+import net.imglib2.img.array.ArrayImg;
+import net.imglib2.img.array.ArrayImgs;
+import net.imglib2.img.basictypeaccess.array.ShortArray;
+import net.imglib2.type.numeric.integer.UnsignedShortType;
+import net.imglib2.util.Util;
+
+public class EllipseTest
+{
+
+	@Test
+	public void testIterateOnce()
+	{
+		final ArrayImg< UnsignedShortType, ShortArray > img = ArrayImgs.unsignedShorts( 512l, 512l );
+
+		final Point center = new Point( 255l, 255l );
+
+		for ( long rx = 1l; rx < 56l; rx++ )
+		{
+			for ( long ry = 1l; ry < 56l; ry++ )
+			{
+				Ellipses.inc( img, center, rx, ry );
+				final EllipseCursor< UnsignedShortType > cursor = new EllipseCursor<>( img, center, rx, ry );
+				while ( cursor.hasNext() )
+				{
+					cursor.fwd();
+					assertEquals( "For radii (" + rx + ", " + ry + "), pixel at coordinates " +
+							Util.printCoordinates( cursor ) + " has not been iterated one time.",
+							1, cursor.get().get() );
+				}
+				// Reset image to 0.
+				for ( final UnsignedShortType p : img )
+					p.setZero();
+			}
+		}
+	}
+
+	@Test
+	public void testDistanceToCenter()
+	{
+		final ArrayImg< UnsignedShortType, ShortArray > img = ArrayImgs.unsignedShorts( 512l, 512l );
+
+		final Point center = new Point( 255l, 255l );
+		final long[] pos = new long[ img.numDimensions() ];
+
+		for ( long r = 1l; r < 256l; r++ )
+		{
+			final EllipseCursor< UnsignedShortType > cursor = new EllipseCursor<>( img, center, r, r );
+			while ( cursor.hasNext() )
+			{
+				cursor.fwd();
+				cursor.localize( pos );
+
+				double d2 = 0.;
+				for ( int d = 0; d < img.numDimensions(); d++ )
+				{
+					final double dx = center.getDoublePosition( d ) - cursor.getDoublePosition( d );
+					d2 += dx * dx;
+				}
+				final double dist = Math.sqrt( d2 );
+
+				assertEquals( "Ellipse coordinates " + Util.printCoordinates( cursor ) + " is too far from expected radius " + r + ".",
+						r, dist, 0.5 );
+			}
+		}
+	}
+}