Merge remote-tracking branch 'upstream/master' into fork_sync

BDV N5 format.md

+# BigDataViewer N5 format
+
+The BigDataViewer N5 back-end (`format="bdv.n5"`) requires a N5 dataset with a specific group hierarchy and attributes.
+
+Multi-channel (-angle, -tile, -illumination) time-series as
+multi-resolution 3D stacks are organized in the following N5 hierarchy:
+
+```
+\
+├── setup0
+│   ├── attributes.json {"downsamplingFactors":[[1,1,1],[2,2,2]],"dataType":"uint8"}
+│   ├── timepoint0
+│   │   ├── s0
+│   │   │   ├── attributes.json {"dataType":"uint8","compression":{"type":"bzip2","blockSize":9},"blockSize":[16,16,16],"dimensions":[400,400,25]}
+│   │   │   ┊
+│   │   │
+│   │   ├── s1
+│   │   ┊
+│   │
+│   ├── timepoint1
+│   ┊
+│
+├── setup1
+┊
+```
+
+Each 3D stack is stored as a dataset with path formatted as `/setup%d/timepoint%d/s%d`.
+Here, `setup` number is flattened integer ID of channel, angle, tile, illumination, etc.,
+`timepoint` is the integer ID of the time point, and `s` is the scale level of the multi-resolution pyramid.
+
+## setup attributes
+Each `setup` group has attributes
+```
+"downsamplingFactors" : [[1,1,1], [2,2,1], ...]
+"dataType":"uint8"
+```
+that specify downsampling scheme and datatype, which are the same for all timepoints.
+`downsamplingFactors` specifies power-of-two downscaling factors for each scale level (with respect to full resolution `s0`, which always has `[1,1,1]`).
+`dataType` is one of {uint8, uint16, uint32, uint64, int8, int16, int32, int64, float32, float64}.
+
+> TODO: Additional metadata (for example identifying `setup3` as channel 3, tile 124, etc.) could be replicated from the XML.
+The idea would be that parts of a dataset can be used independent of BDV, without the XML.
+We should agree on standard attributes for this.
+
+## timepoint attributes
+`timepoint` has no mandatory attributes.
+
+For compatibility with Paintera, when exporting to N5 we put the `"multiScale" : true`, and `"resolution" : [x,y,z]` attributes.
+
+## scale level attributes
+`s0`, `s1`, etc. have the mandatory N5 dataset attributes.
+
+For compatibility with Paintera, when exporting to N5 we put the `"downsamplingFactors": [x,y,z]` attribute.
+
+> TODO: Additional metadata (for example scaled resolution and affine transform) could be replicated from the XML.
+The idea would be that an individual stack can be used independent of BDV, without the XML.
+We should agree on standard attributes for this.

LICENSE.txt

-Copyright (c) 2012 - 2016, Tobias Pietzsch, Stephan Saalfeld, Stephan Preibisch,
-Jean-Yves Tinevez, HongKee Moon, Johannes Schindelin, Curtis Rueden, John Bogovic
+Copyright (c) 2012 - 2020, BigDataViewer developers.
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification,

pom.xml

@@ -5,13 +5,13 @@
 	<parent>
 		<groupId>org.scijava</groupId>
 		<artifactId>pom-scijava</artifactId>
-		<version>27.0.1</version>
+		<version>29.2.1</version>
 		<relativePath />
 	</parent>
 
 	<groupId>sc.fiji</groupId>
 	<artifactId>bigdataviewer-core</artifactId>
-	<version>7.0.1-SNAPSHOT</version>
+	<version>10.0.3-SNAPSHOT</version>
 
 	<name>BigDataViewer Core</name>
 	<description>BigDataViewer core classes with minimal dependencies.</description>
@@ -134,12 +134,9 @@
 		<package-name>bdv</package-name>
 		<license.licenseName>bsd_2</license.licenseName>
 		<license.copyrightOwners>BigDataViewer developers.</license.copyrightOwners>
-		<enforcer.skip>true</enforcer.skip>
 
 		<!-- NB: Deploy releases to the SciJava Maven repository. -->
 		<releaseProfiles>deploy-to-scijava</releaseProfiles>
-
-		<imglib2-cache.version>1.0.0-beta-12</imglib2-cache.version>
 	</properties>
 
 	<repositories>
@@ -162,10 +159,6 @@
 			<groupId>net.imglib2</groupId>
 			<artifactId>imglib2-cache</artifactId>
 		</dependency>
-		<dependency>
-			<groupId>net.imglib2</groupId>
-			<artifactId>imglib2-ui</artifactId>
-		</dependency>
 		<dependency>
 			<groupId>net.imglib2</groupId>
 			<artifactId>imglib2-algorithm</artifactId>
@@ -193,8 +186,20 @@
 		<dependency>
 			<groupId>org.scijava</groupId>
 			<artifactId>scijava-listeners</artifactId>
-			<version>1.0.0-beta-2</version>
 		</dependency>
+		<dependency>
+			<groupId>org.janelia.saalfeldlab</groupId>
+			<artifactId>n5-imglib2</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.janelia.saalfeldlab</groupId>
+			<artifactId>n5</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.miglayout</groupId>
+			<artifactId>miglayout-swing</artifactId>
+		</dependency>
+
 		<!-- test dependencies -->
 		<dependency>
 			<groupId>junit</groupId>

src/main/java/bdv/AbstractCachedViewerSetupImgLoader.java

+/*-
+ * #%L
+ * BigDataViewer core classes with minimal dependencies.
+ * %%
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 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.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * #L%
+ */
 package bdv;
 
 import bdv.img.cache.CacheArrayLoader;
@@ -16,7 +44,7 @@ import net.imglib2.type.NativeType;
 /**
  * Abstract {@link ViewerSetupImgLoader} with a VolatileGlobalCellCache.
  *
- * @author Stephan Saalfeld <saalfelds@janelia.hhmi.org>
+ * @author Stephan Saalfeld
  */
 abstract public class AbstractCachedViewerSetupImgLoader< T extends NativeType< T > , V extends Volatile< T > & NativeType< V >, A extends VolatileAccess >
 	extends AbstractViewerSetupImgLoader< T, V >

src/main/java/bdv/AbstractSpimSource.java

 /*
  * #%L
- * BigDataViewer core classes with minimal dependencies
+ * BigDataViewer core classes with minimal dependencies.
  * %%
- * Copyright (C) 2012 - 2016 Tobias Pietzsch, Stephan Saalfeld, Stephan Preibisch,
- * Jean-Yves Tinevez, HongKee Moon, Johannes Schindelin, Curtis Rueden, John Bogovic
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
  * %%
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

src/main/java/bdv/AbstractViewerSetupImgLoader.java

 /*
  * #%L
- * BigDataViewer core classes with minimal dependencies
+ * BigDataViewer core classes with minimal dependencies.
  * %%
- * Copyright (C) 2012 - 2016 Tobias Pietzsch, Stephan Saalfeld, Stephan Preibisch,
- * Jean-Yves Tinevez, HongKee Moon, Johannes Schindelin, Curtis Rueden, John Bogovic
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
  * %%
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

src/main/java/bdv/BigDataViewerActions.java

 /*
  * #%L
- * BigDataViewer core classes with minimal dependencies
+ * BigDataViewer core classes with minimal dependencies.
  * %%
- * Copyright (C) 2012 - 2016 Tobias Pietzsch, Stephan Saalfeld, Stephan Preibisch,
- * Jean-Yves Tinevez, HongKee Moon, Johannes Schindelin, Curtis Rueden, John Bogovic
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
  * %%
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -57,6 +56,8 @@ public class BigDataViewerActions extends Actions
 	public static final String MANUAL_TRANSFORM = "toggle manual transformation";
 	public static final String SAVE_SETTINGS = "save settings";
 	public static final String LOAD_SETTINGS = "load settings";
+	public static final String EXPAND_CARDS = "expand and focus cards panel";
+	public static final String COLLAPSE_CARDS = "collapse cards panel";
 	public static final String RECORD_MOVIE = "record movie";
 	public static final String RECORD_MAX_PROJECTION_MOVIE = "record max projection movie";
 	public static final String SET_BOOKMARK = "set bookmark";
@@ -72,6 +73,8 @@ public class BigDataViewerActions extends Actions
 	static final String[] RECORD_MOVIE_KEYS                = new String[] { "F10" };
 	static final String[] SAVE_SETTINGS_KEYS               = new String[] { "F11" };
 	static final String[] LOAD_SETTINGS_KEYS               = new String[] { "F12" };
+	public static final String[] EXPAND_CARDS_KEYS         = new String[] { "P" };
+	public static final String[] COLLAPSE_CARDS_KEYS       = new String[] { "shift P", "shift ESCAPE" };
 	static final String[] GO_TO_BOOKMARK_KEYS              = new String[] { "B" };
 	static final String[] GO_TO_BOOKMARK_ROTATION_KEYS     = new String[] { "O" };
 	static final String[] SET_BOOKMARK_KEYS                = new String[] { "shift B" };
@@ -104,6 +107,8 @@ public class BigDataViewerActions extends Actions
 		actions.manualTransform( bdv.manualTransformationEditor );
 		actions.runnableAction( bdv::loadSettings, LOAD_SETTINGS, LOAD_SETTINGS_KEYS );
 		actions.runnableAction( bdv::saveSettings, SAVE_SETTINGS, SAVE_SETTINGS_KEYS );
+		actions.runnableAction( bdv::expandAndFocusCardPanel, EXPAND_CARDS, EXPAND_CARDS_KEYS );
+		actions.runnableAction( bdv::collapseCardPanel, COLLAPSE_CARDS, COLLAPSE_CARDS_KEYS );
 
 		actions.install( inputActionBindings, "bdv" );
 	}
@@ -119,11 +124,13 @@ public class BigDataViewerActions extends Actions
 		new ToggleDialogAction( name, dialog ).put( getActionMap() );
 	}
 
+	@Deprecated
 	public void dialog( final BrightnessDialog brightnessDialog )
 	{
 		toggleDialogAction( brightnessDialog, BRIGHTNESS_SETTINGS, BRIGHTNESS_SETTINGS_KEYS );
 	}
 
+	@Deprecated
 	public void dialog( final VisibilityAndGroupingDialog visibilityAndGroupingDialog )
 	{
 		toggleDialogAction( visibilityAndGroupingDialog, VISIBILITY_AND_GROUPING, VISIBILITY_AND_GROUPING_KEYS );

src/main/java/bdv/SpimSource.java

 /*
  * #%L
- * BigDataViewer core classes with minimal dependencies
+ * BigDataViewer core classes with minimal dependencies.
  * %%
- * Copyright (C) 2012 - 2016 Tobias Pietzsch, Stephan Saalfeld, Stephan Preibisch,
- * Jean-Yves Tinevez, HongKee Moon, Johannes Schindelin, Curtis Rueden, John Bogovic
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
  * %%
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

src/main/java/bdv/TransformEventHandler.java

+/*
+ * #%L
+ * BigDataViewer core classes with minimal dependencies.
+ * %%
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 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.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * #L%
+ */
+package bdv;
+
+import org.scijava.ui.behaviour.util.Behaviours;
+
+/**
+ * Change a transformation in response to user input (mouse events, key events, etc.)
+ *
+ * The {@link TransformEventHandler} receives notifications about changes of the
+ * canvas size (it may react for example by changing the scale of the
+ * transformation accordingly).
+ *
+ * @author Tobias Pietzsch
+ */
+public interface TransformEventHandler
+{
+	/**
+	 * Install transformation behaviours into the specified {@code behaviours} contrainer.
+	 */
+	void install( Behaviours behaviours );
+
+	/**
+	 * This is called, when the screen size of the canvas (the component
+	 * displaying the image and generating mouse events) changes. This can be
+	 * used to determine screen coordinates to keep fixed while zooming or
+	 * rotating with the keyboard, e.g., set these to
+	 * <em>(width/2, height/2)</em>. It can also be used to update the current
+	 * source-to-screen transform, e.g., to change the zoom along with the
+	 * canvas size.
+	 *
+	 * @param width
+	 *            the new canvas width.
+	 * @param height
+	 *            the new canvas height.
+	 * @param updateTransform
+	 *            whether the current source-to-screen transform should be
+	 *            updated. This will be <code>false</code> for the initial
+	 *            update of a new {@link TransformEventHandler} and
+	 *            <code>true</code> on subsequent calls.
+	 */
+	void setCanvasSize( int width, int height, boolean updateTransform );
+}

src/main/java/bdv/TransformEventHandler2D.java

+/*-
+ * #%L
+ * BigDataViewer core classes with minimal dependencies.
+ * %%
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 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.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * #L%
+ */
+package bdv;
+
+import net.imglib2.realtransform.AffineTransform3D;
+import org.scijava.ui.behaviour.Behaviour;
+import org.scijava.ui.behaviour.ClickBehaviour;
+import org.scijava.ui.behaviour.DragBehaviour;
+import org.scijava.ui.behaviour.ScrollBehaviour;
+import org.scijava.ui.behaviour.util.Behaviours;
+
+/**
+ * A {@link TransformEventHandler} that changes an {@link AffineTransform3D}
+ * through a set of {@link Behaviour}s.
+ *
+ * @author Tobias Pietzsch
+ */
+public class TransformEventHandler2D implements TransformEventHandler
+{
+	// -- behaviour names --
+
+	public static final String DRAG_TRANSLATE = "2d drag translate";
+	public static final String DRAG_ROTATE = "2d drag rotate";
+
+	public static final String ZOOM_NORMAL = "2d scroll zoom";
+	public static final String SCROLL_TRANSLATE = "2d scroll translate";
+	public static final String SCROLL_ROTATE = "2d scroll rotate";
+	public static final String ROTATE_LEFT = "2d rotate left";
+	public static final String ROTATE_RIGHT = "2d rotate right";
+	public static final String KEY_ZOOM_IN = "2d zoom in";
+	public static final String KEY_ZOOM_OUT = "2d zoom out";
+
+	public static final String ZOOM_FAST = "2d scroll zoom fast";
+	public static final String SCROLL_TRANSLATE_FAST = "2d scroll translate fast";
+	public static final String SCROLL_ROTATE_FAST = "2d scroll rotate fast";
+	public static final String ROTATE_LEFT_FAST = "2d rotate left fast";
+	public static final String ROTATE_RIGHT_FAST = "2d rotate right fast";
+	public static final String KEY_ZOOM_IN_FAST = "2d zoom in fast";
+	public static final String KEY_ZOOM_OUT_FAST = "2d zoom out fast";
+
+	public static final String ZOOM_SLOW = "2d scroll zoom slow";
+	public static final String SCROLL_TRANSLATE_SLOW = "2d scroll translate slow";
+	public static final String SCROLL_ROTATE_SLOW = "2d scroll rotate slow";
+	public static final String ROTATE_LEFT_SLOW = "2d rotate left slow";
+	public static final String ROTATE_RIGHT_SLOW = "2d rotate right slow";
+	public static final String KEY_ZOOM_IN_SLOW = "2d zoom in slow";
+	public static final String KEY_ZOOM_OUT_SLOW = "2d zoom out slow";
+
+	// -- default shortcuts --
+
+	private static final String[] DRAG_TRANSLATE_KEYS = new String[] { "button2", "button3" };
+	private static final String[] DRAG_ROTATE_KEYS = new String[] { "button1" };
+
+	private static final String[] ZOOM_NORMAL_KEYS = new String[] { "scroll", "meta scroll", "ctrl shift scroll" };
+	private static final String[] SCROLL_TRANSLATE_KEYS = new String[] { "not mapped" };
+	private static final String[] SCROLL_ROTATE_KEYS = new String[] { "not mapped" };
+	private static final String[] ROTATE_LEFT_KEYS = new String[] { "LEFT" };
+	private static final String[] ROTATE_RIGHT_KEYS = new String[] { "RIGHT" };
+	private static final String[] KEY_ZOOM_IN_KEYS = new String[] { "UP" };
+	private static final String[] KEY_ZOOM_OUT_KEYS = new String[] { "DOWN" };
+
+	private static final String[] ZOOM_FAST_KEYS = new String[] { "shift scroll" };
+	private static final String[] SCROLL_TRANSLATE_FAST_KEYS = new String[] { "not mapped" };
+	private static final String[] SCROLL_ROTATE_FAST_KEYS = new String[] { "not mapped" };
+	private static final String[] ROTATE_LEFT_FAST_KEYS = new String[] { "shift LEFT" };
+	private static final String[] ROTATE_RIGHT_FAST_KEYS = new String[] { "shift RIGHT" };
+	private static final String[] KEY_ZOOM_IN_FAST_KEYS = new String[] { "shift UP" };
+	private static final String[] KEY_ZOOM_OUT_FAST_KEYS = new String[] { "shift DOWN" };
+
+	private static final String[] ZOOM_SLOW_KEYS = new String[] { "ctrl scroll" };
+	private static final String[] SCROLL_TRANSLATE_SLOW_KEYS = new String[] { "not mapped" };
+	private static final String[] SCROLL_ROTATE_SLOW_KEYS = new String[] { "not mapped" };
+	private static final String[] ROTATE_LEFT_SLOW_KEYS = new String[] { "ctrl LEFT" };
+	private static final String[] ROTATE_RIGHT_SLOW_KEYS = new String[] { "ctrl RIGHT" };
+	private static final String[] KEY_ZOOM_IN_SLOW_KEYS = new String[] { "ctrl UP" };
+	private static final String[] KEY_ZOOM_OUT_SLOW_KEYS = new String[] { "ctrl DOWN" };
+
+	// -- behaviours --
+
+	private final DragTranslate dragTranslate;
+	private final DragRotate dragRotate;
+	private final Zoom zoom;
+	private final Zoom zoomFast;
+	private final Zoom zoomSlow;
+	private final ScrollTranslate scrollTranslate;
+	private final ScrollTranslate scrollTranslateFast;
+	private final ScrollTranslate scrollTranslateSlow;
+	private final ScrollRotate scrollRotate;
+	private final ScrollRotate scrollRotateFast;
+	private final ScrollRotate scrollRotateSlow;
+	private final KeyRotate keyRotateLeft;
+	private final KeyRotate keyRotateLeftFast;
+	private final KeyRotate keyRotateLeftSlow;
+	private final KeyRotate keyRotateRight;
+	private final KeyRotate keyRotateRightFast;
+	private final KeyRotate keyRotateRightSlow;
+	private final KeyZoom keyZoomIn;
+	private final KeyZoom keyZoomInFast;
+	private final KeyZoom keyZoomInSlow;
+	private final KeyZoom keyZoomOut;
+	private final KeyZoom keyZoomOutFast;
+	private final KeyZoom keyZoomOutSlow;
+
+	private static final double[] speed = { 1.0, 10.0, 0.1 };
+
+	/**
+	 * Copy of transform when mouse dragging started.
+	 */
+	private final AffineTransform3D affineDragStart = new AffineTransform3D();
+
+	/**
+	 * Current transform during mouse dragging.
+	 */
+	private final AffineTransform3D affineDragCurrent = new AffineTransform3D();
+
+	/**
+	 * Coordinates where mouse dragging started.
+	 */
+	private double oX, oY;
+
+	/**
+	 * The screen size of the canvas (the component displaying the image and
+	 * generating mouse events).
+	 */
+	private int canvasW = 1, canvasH = 1;
+
+	/**
+	 * Screen coordinates to keep centered while zooming or rotating with the
+	 * keyboard. These are set to <em>(canvasW/2, canvasH/2)</em>
+	 */
+	private int centerX = 0, centerY = 0;
+
+	private final TransformState transform;
+
+	public TransformEventHandler2D( final TransformState transform )
+	{
+		this.transform = transform;
+
+		dragTranslate = new DragTranslate();
+		dragRotate = new DragRotate();
+
+		scrollTranslate = new ScrollTranslate( speed[ 0 ] );
+		scrollTranslateFast = new ScrollTranslate( speed[ 1 ] );
+		scrollTranslateSlow = new ScrollTranslate( speed[ 2 ] );
+
+		zoom = new Zoom( speed[ 0 ] );
+		zoomFast = new Zoom( speed[ 1 ] );
+		zoomSlow = new Zoom( speed[ 2 ] );
+
+		scrollRotate = new ScrollRotate( 2 * speed[ 0 ] );
+		scrollRotateFast = new ScrollRotate( 2 * speed[ 1 ] );
+		scrollRotateSlow = new ScrollRotate( 2 * speed[ 2 ] );
+
+		keyRotateLeft = new KeyRotate( speed[ 0 ] );
+		keyRotateLeftFast = new KeyRotate( speed[ 1 ] );
+		keyRotateLeftSlow = new KeyRotate( speed[ 2 ] );
+		keyRotateRight = new KeyRotate( -speed[ 0 ] );
+		keyRotateRightFast = new KeyRotate( -speed[ 1 ] );
+		keyRotateRightSlow = new KeyRotate( -speed[ 2 ] );
+
+		keyZoomIn = new KeyZoom( speed[ 0 ] );
+		keyZoomInFast = new KeyZoom( speed[ 1 ] );
+		keyZoomInSlow = new KeyZoom( speed[ 2 ] );
+		keyZoomOut = new KeyZoom( -speed[ 0 ] );
+		keyZoomOutFast = new KeyZoom( -speed[ 1 ] );
+		keyZoomOutSlow = new KeyZoom( -speed[ 2 ] );
+	}
+
+	@Override
+	public void install( final Behaviours behaviours )
+	{
+		behaviours.behaviour( dragTranslate, DRAG_TRANSLATE, DRAG_TRANSLATE_KEYS );
+		behaviours.behaviour( dragRotate, DRAG_ROTATE,  DRAG_ROTATE_KEYS );
+
+		behaviours.behaviour( scrollTranslate, SCROLL_TRANSLATE, SCROLL_TRANSLATE_KEYS );
+		behaviours.behaviour( scrollTranslateFast, SCROLL_TRANSLATE_FAST, SCROLL_TRANSLATE_FAST_KEYS );
+		behaviours.behaviour( scrollTranslateSlow, SCROLL_TRANSLATE_SLOW, SCROLL_TRANSLATE_SLOW_KEYS );
+
+		behaviours.behaviour( zoom, ZOOM_NORMAL, ZOOM_NORMAL_KEYS );
+		behaviours.behaviour( zoomFast, ZOOM_FAST, ZOOM_FAST_KEYS );
+		behaviours.behaviour( zoomSlow, ZOOM_SLOW, ZOOM_SLOW_KEYS );
+
+		behaviours.behaviour( scrollRotate, SCROLL_ROTATE, SCROLL_ROTATE_KEYS );
+		behaviours.behaviour( scrollRotateFast, SCROLL_ROTATE_FAST, SCROLL_ROTATE_FAST_KEYS );
+		behaviours.behaviour( scrollRotateSlow, SCROLL_ROTATE_SLOW, SCROLL_ROTATE_SLOW_KEYS );
+
+		behaviours.behaviour( keyRotateLeft, ROTATE_LEFT, ROTATE_LEFT_KEYS );
+		behaviours.behaviour( keyRotateLeftFast, ROTATE_LEFT_FAST, ROTATE_LEFT_FAST_KEYS );
+		behaviours.behaviour( keyRotateLeftSlow, ROTATE_LEFT_SLOW, ROTATE_LEFT_SLOW_KEYS );
+		behaviours.behaviour( keyRotateRight, ROTATE_RIGHT, ROTATE_RIGHT_KEYS );
+		behaviours.behaviour( keyRotateRightFast, ROTATE_RIGHT_FAST, ROTATE_RIGHT_FAST_KEYS );
+		behaviours.behaviour( keyRotateRightSlow, ROTATE_RIGHT_SLOW, ROTATE_RIGHT_SLOW_KEYS );
+
+		behaviours.behaviour( keyZoomIn,  KEY_ZOOM_IN, KEY_ZOOM_IN_KEYS );
+		behaviours.behaviour( keyZoomInFast, KEY_ZOOM_IN_FAST, KEY_ZOOM_IN_FAST_KEYS );
+		behaviours.behaviour( keyZoomInSlow, KEY_ZOOM_IN_SLOW, KEY_ZOOM_IN_SLOW_KEYS );
+		behaviours.behaviour( keyZoomOut, KEY_ZOOM_OUT, KEY_ZOOM_OUT_KEYS );
+		behaviours.behaviour( keyZoomOutFast, KEY_ZOOM_OUT_FAST, KEY_ZOOM_OUT_FAST_KEYS );
+		behaviours.behaviour( keyZoomOutSlow, KEY_ZOOM_OUT_SLOW, KEY_ZOOM_OUT_SLOW_KEYS );
+	}
+
+	@Override
+	public void setCanvasSize( final int width, final int height, final boolean updateTransform )
+	{
+		if ( width == 0 || height == 0 ) {
+			// NB: We are probably in some intermediate layout scenario.
+			// Attempting to trigger a transform update with 0 size will result
+			// in the exception "Matrix is singular" from imglib2-realtrasform.
+			return;
+		}
+		if ( updateTransform )
+		{
+			final AffineTransform3D affine = transform.get();
+			affine.set( affine.get( 0, 3 ) - canvasW / 2, 0, 3 );
+			affine.set( affine.get( 1, 3 ) - canvasH / 2, 1, 3 );
+			affine.scale( ( double ) width / canvasW );
+			affine.set( affine.get( 0, 3 ) + width / 2, 0, 3 );
+			affine.set( affine.get( 1, 3 ) + height / 2, 1, 3 );
+			transform.set( affine );
+		}
+		canvasW = width;
+		canvasH = height;
+		centerX = width / 2;
+		centerY = height / 2;
+	}
+
+	/**
+	 * One step of rotation (radian).
+	 */
+	final private static double step = Math.PI / 180;
+
+	private void scale( final double s, final double x, final double y )
+	{
+		final AffineTransform3D affine = transform.get();
+
+		// center shift
+		affine.set( affine.get( 0, 3 ) - x, 0, 3 );
+		affine.set( affine.get( 1, 3 ) - y, 1, 3 );
+
+		// scale
+		affine.scale( s );
+
+		// center un-shift
+		affine.set( affine.get( 0, 3 ) + x, 0, 3 );
+		affine.set( affine.get( 1, 3 ) + y, 1, 3 );
+
+		transform.set( affine );
+	}
+
+	/**
+	 * Rotate by d radians around Z axis. Keep screen coordinates {@code (centerX, centerY)} fixed.
+	 */
+	private void rotate( final AffineTransform3D affine, final double d )
+	{
+		// center shift
+		affine.set( affine.get( 0, 3 ) - centerX, 0, 3 );
+		affine.set( affine.get( 1, 3 ) - centerY, 1, 3 );
+
+		// rotate
+		affine.rotate( 2, d );
+
+		// center un-shift
+		affine.set( affine.get( 0, 3 ) + centerX, 0, 3 );
+		affine.set( affine.get( 1, 3 ) + centerY, 1, 3 );
+	}
+
+	private class DragRotate implements DragBehaviour
+	{
+		@Override
+		public void init( final int x, final int y )
+		{
+			oX = x;
+			oY = y;
+			transform.get( affineDragStart );
+		}
+
+		@Override
+		public void drag( final int x, final int y )
+		{
+			final double dX = x - centerX;
+			final double dY = y - centerY;
+			final double odX = oX - centerX;
+			final double odY = oY - centerY;
+			final double theta = Math.atan2( dY, dX ) - Math.atan2( odY, odX );
+
+			affineDragCurrent.set( affineDragStart );
+			rotate( affineDragCurrent, theta );
+			transform.set( affineDragCurrent );
+		}
+
+		@Override
+		public void end( final int x, final int y )
+		{}
+	}
+
+	private class ScrollRotate implements ScrollBehaviour
+	{
+		private final double speed;
+
+		public ScrollRotate( final double speed )
+		{
+			this.speed = speed;
+		}
+
+		@Override
+		public void scroll( final double wheelRotation, final boolean isHorizontal, final int x, final int y )
+		{
+			final AffineTransform3D affine = transform.get();
+
+			final double theta = speed * wheelRotation * Math.PI / 180.0;
+
+			// center shift
+			affine.set( affine.get( 0, 3 ) - x, 0, 3 );
+			affine.set( affine.get( 1, 3 ) - y, 1, 3 );
+
+			affine.rotate( 2, theta );
+
+			// center un-shift
+			affine.set( affine.get( 0, 3 ) + x, 0, 3 );
+			affine.set( affine.get( 1, 3 ) + y, 1, 3 );
+
+			transform.set( affine );
+		}
+	}
+
+	private class DragTranslate implements DragBehaviour
+	{
+		@Override
+		public void init( final int x, final int y )
+		{
+			oX = x;
+			oY = y;
+			transform.get( affineDragStart );
+		}
+
+		@Override
+		public void drag( final int x, final int y )
+		{
+			final double dX = oX - x;
+			final double dY = oY - y;
+
+			affineDragCurrent.set( affineDragStart );
+			affineDragCurrent.set( affineDragCurrent.get( 0, 3 ) - dX, 0, 3 );
+			affineDragCurrent.set( affineDragCurrent.get( 1, 3 ) - dY, 1, 3 );
+
+			transform.set( affineDragCurrent );
+		}
+
+		@Override
+		public void end( final int x, final int y )
+		{}
+	}
+
+	private class ScrollTranslate implements ScrollBehaviour
+	{
+
+		private final double speed;
+
+		public ScrollTranslate( final double speed )
+		{
+			this.speed = speed;
+		}
+
+		@Override
+		public void scroll( final double wheelRotation, final boolean isHorizontal, final int x, final int y )
+		{
+			final AffineTransform3D affine = transform.get();
+
+			final double d = -wheelRotation * 10 * speed;
+			if ( isHorizontal )
+				affine.translate( d, 0, 0 );
+			else
+				affine.translate( 0, d, 0 );
+
+			transform.set( affine );
+		}
+	}
+
+	private class Zoom implements ScrollBehaviour
+	{
+
+		private final double speed;
+
+		public Zoom( final double speed )
+		{
+			this.speed = speed;
+		}
+
+		@Override
+		public void scroll( final double wheelRotation, final boolean isHorizontal, final int x, final int y )
+		{
+			final double s = speed * wheelRotation;
+			final double dScale = 1.0 + 0.05 * Math.abs( s );
+			if ( s > 0 )
+				scale( 1.0 / dScale, x, y );
+			else
+				scale( dScale, x, y );
+		}
+	}
+
+	private class KeyRotate implements ClickBehaviour
+	{
+		private final double speed;
+
+		public KeyRotate( final double speed )
+		{
+			this.speed = speed;
+		}
+
+		@Override
+		public void click( final int x, final int y )
+		{
+			final AffineTransform3D affine = transform.get();
+			rotate( affine, step * speed );
+			transform.set( affine );
+		}
+	}
+
+	private class KeyZoom implements ClickBehaviour
+	{
+		private final double dScale;
+
+		public KeyZoom( final double speed )
+		{
+			if ( speed > 0 )
+				dScale = 1.0 + 0.1 * speed;
+			else
+				dScale = 1.0 / ( 1.0 - 0.1 * speed );
+		}
+
+		@Override
+		public void click( final int x, final int y )
+		{
+			scale( dScale, centerX, centerY );
+		}
+	}
+}

src/main/java/bdv/BehaviourTransformEventHandler.java → src/main/java/bdv/TransformEventHandlerFactory.java

-/*-
+/*
  * #%L
- * BigDataViewer core classes with minimal dependencies
+ * BigDataViewer core classes with minimal dependencies.
  * %%
- * Copyright (C) 2012 - 2016 Tobias Pietzsch, Stephan Saalfeld, Stephan Preibisch,
- * Jean-Yves Tinevez, HongKee Moon, Johannes Schindelin, Curtis Rueden, John Bogovic
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
  * %%
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -29,11 +28,15 @@
  */
 package bdv;
 
-import org.scijava.ui.behaviour.util.TriggerBehaviourBindings;
-
-import net.imglib2.ui.TransformEventHandler;
-
-public interface BehaviourTransformEventHandler< A > extends TransformEventHandler< A >
+/**
+ * Factory for {@code TransformEventHandler}.
+ *
+ * @author Tobias Pietzsch
+ */
+public interface TransformEventHandlerFactory
 {
-	public void install( final TriggerBehaviourBindings bindings );
+	/**
+	 * Create a new {@code TransformEventHandler}.
+	 */
+	TransformEventHandler create( TransformState transformState );
 }

src/main/java/bdv/viewer/render/TransformAwareRenderTarget.java → src/main/java/bdv/TransformState.java

-/*
+/*-
  * #%L
- * BigDataViewer core classes with minimal dependencies
+ * BigDataViewer core classes with minimal dependencies.
  * %%
- * Copyright (C) 2012 - 2016 Tobias Pietzsch, Stephan Saalfeld, Stephan Preibisch,
- * Jean-Yves Tinevez, HongKee Moon, Johannes Schindelin, Curtis Rueden, John Bogovic
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
  * %%
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -27,28 +26,53 @@
  * POSSIBILITY OF SUCH DAMAGE.
  * #L%
  */
-package bdv.viewer.render;
-
-import java.awt.image.BufferedImage;
+package bdv;
 
+import java.util.function.Consumer;
 import net.imglib2.realtransform.AffineTransform3D;
-import net.imglib2.ui.RenderTarget;
-import net.imglib2.ui.TransformListener;
 
-public interface TransformAwareRenderTarget extends RenderTarget
+public interface TransformState
 {
 	/**
-	 * Set the {@link BufferedImage} that is to be drawn on the canvas, and the
-	 * transform with which this image was created.
+	 * Get the current transform.
 	 *
-	 * @param img
-	 *            image to draw (may be null).
+	 * @param transform
+	 *     is set to the current transform
 	 */
-	public BufferedImage setBufferedImageAndTransform( final BufferedImage img, final AffineTransform3D transform );
+	void get( AffineTransform3D transform );
 
-	public void addTransformListener( final TransformListener< AffineTransform3D > listener );
+	/**
+	 * Get the current transform.
+	 *
+	 * @return a copy of the current transform
+	 */
+	default AffineTransform3D get()
+	{
+		final AffineTransform3D transform = new AffineTransform3D();
+		get( transform );
+		return transform;
+	}
+
+	/**
+	 * Set the transform.
+	 */
+	void set( AffineTransform3D transform );
 
-	public void addTransformListener( final TransformListener< AffineTransform3D > listener, final int index );
+	static TransformState from( Consumer< AffineTransform3D > get, Consumer< AffineTransform3D > set )
+	{
+		return new TransformState()
+		{
+			@Override
+			public void get( final AffineTransform3D transform )
+			{
+				get.accept( transform );
+			}
 
-	public void removeTransformListener( final TransformListener< AffineTransform3D > listener );
+			@Override
+			public void set( final AffineTransform3D transform )
+			{
+				set.accept( transform );
+			}
+		};
+	}
 }

src/main/java/bdv/ViewerImgLoader.java

 /*
  * #%L
- * BigDataViewer core classes with minimal dependencies
+ * BigDataViewer core classes with minimal dependencies.
  * %%
- * Copyright (C) 2012 - 2016 Tobias Pietzsch, Stephan Saalfeld, Stephan Preibisch,
- * Jean-Yves Tinevez, HongKee Moon, Johannes Schindelin, Curtis Rueden, John Bogovic
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
  * %%
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -35,7 +34,7 @@ import mpicbg.spim.data.generic.sequence.BasicMultiResolutionImgLoader;
 public interface ViewerImgLoader extends BasicMultiResolutionImgLoader
 {
 	@Override
-	public ViewerSetupImgLoader< ?, ? > getSetupImgLoader( final int setupId );
+	ViewerSetupImgLoader< ?, ? > getSetupImgLoader( final int setupId );
 
-	public CacheControl getCacheControl();
+	CacheControl getCacheControl();
 }

src/main/java/bdv/ViewerSetupImgLoader.java

 /*
  * #%L
- * BigDataViewer core classes with minimal dependencies
+ * BigDataViewer core classes with minimal dependencies.
  * %%
- * Copyright (C) 2012 - 2016 Tobias Pietzsch, Stephan Saalfeld, Stephan Preibisch,
- * Jean-Yves Tinevez, HongKee Moon, Johannes Schindelin, Curtis Rueden, John Bogovic
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
  * %%
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -36,7 +35,7 @@ import net.imglib2.Volatile;
 
 public interface ViewerSetupImgLoader< T, V extends Volatile< T > > extends BasicMultiResolutionSetupImgLoader< T >
 {
-	public RandomAccessibleInterval< V > getVolatileImage( final int timepointId, final int level, ImgLoaderHint... hints );
+	RandomAccessibleInterval< V > getVolatileImage( final int timepointId, final int level, ImgLoaderHint... hints );
 
-	public V getVolatileImageType();
+	V getVolatileImageType();
 }

src/main/java/bdv/VolatileSpimSource.java

 /*
  * #%L
- * BigDataViewer core classes with minimal dependencies
+ * BigDataViewer core classes with minimal dependencies.
  * %%
- * Copyright (C) 2012 - 2016 Tobias Pietzsch, Stephan Saalfeld, Stephan Preibisch,
- * Jean-Yves Tinevez, HongKee Moon, Johannes Schindelin, Curtis Rueden, John Bogovic
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
  * %%
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
- *
+ * 
  * 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.
- *
+ * 
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

src/main/java/bdv/cache/CacheControl.java

 /*
  * #%L
- * BigDataViewer core classes with minimal dependencies
+ * BigDataViewer core classes with minimal dependencies.
  * %%
- * Copyright (C) 2012 - 2016 Tobias Pietzsch, Stephan Saalfeld, Stephan Preibisch,
- * Jean-Yves Tinevez, HongKee Moon, Johannes Schindelin, Curtis Rueden, John Bogovic
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
  * %%
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -40,7 +39,7 @@ import bdv.img.cache.VolatileGlobalCellCache;
  * {@link VolatileGlobalCellCache}, these can be simply implemented to do
  * nothing.
  *
- * @author Tobias Pietzsch <tobias.pietzsch@gmail.com>
+ * @author Tobias Pietzsch
  */
 public interface CacheControl
 {
@@ -54,12 +53,12 @@ public interface CacheControl
 	 * previously enqueued requests to be enqueued again for the new frame.
 	 * </ul>
 	 */
-	public void prepareNextFrame();
+	void prepareNextFrame();
 
 	/**
 	 * {@link CacheControl} that does nothing.
 	 */
-	public static class Dummy implements CacheControl
+	class Dummy implements CacheControl
 	{
 		@Override
 		public void prepareNextFrame()
@@ -70,7 +69,7 @@ public interface CacheControl
 	 * {@link CacheControl} backed by a set of {@link CacheControl}s.
 	 * {@link #prepareNextFrame()} forwards to all of them.
 	 */
-	public static class CacheControls implements CacheControl
+	class CacheControls implements CacheControl
 	{
 		private final CopyOnWriteArrayList< CacheControl > cacheControls = new CopyOnWriteArrayList<>();
 
@@ -94,6 +93,11 @@ public interface CacheControl
 			cacheControls.remove( cacheControl );
 		}
 
+		public synchronized void clear()
+		{
+			cacheControls.clear();
+		}
+
 		@Override
 		public void prepareNextFrame()
 		{

src/main/java/bdv/export/CopyBlock.java

+/*-
+ * #%L
+ * BigDataViewer core classes with minimal dependencies.
+ * %%
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 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.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * #L%
+ */
+package bdv.export;
+
+import java.util.Arrays;
+import net.imglib2.RandomAccess;
+import net.imglib2.loops.ClassCopyProvider;
+import net.imglib2.type.numeric.RealType;
+
+public interface CopyBlock< T extends RealType< T > >
+{
+	void copyBlock( final RandomAccess< T > in, final RandomAccess< T > out, final int[] dimensions );
+
+	static < T extends RealType< T > > CopyBlock< T > create(
+			final int numDimensions,
+			final Class< ?  > pixelTypeClass,
+			final Class< ? > inAccessClass )
+	{
+		return CopyBlockInstances.create( numDimensions, pixelTypeClass, inAccessClass );
+	}
+}
+
+class CopyBlockInstances
+{
+	@SuppressWarnings( "rawtypes" )
+	private static ClassCopyProvider< CopyBlock > provider;
+
+	@SuppressWarnings( "unchecked" )
+	public static < T extends RealType< T > > CopyBlock< T > create(
+			final int numDimensions,
+			final Class< ?  > pixelTypeClass,
+			final Class< ? > inAccessClass )
+	{
+		if ( provider == null )
+		{
+			synchronized ( CopyBlockInstances.class )
+			{
+				if ( provider == null )
+					provider = new ClassCopyProvider<>( Imp.class, CopyBlock.class, int.class );
+			}
+		}
+
+		Object key = Arrays.asList( numDimensions, pixelTypeClass, inAccessClass );
+		return provider.newInstanceForKey( key, numDimensions );
+	}
+
+	public static class Imp< T extends RealType< T > > implements CopyBlock< T >
+	{
+		private final int n;
+
+		public Imp( final int n )
+		{
+			if ( n < 1 || n > 3 )
+				throw new IllegalArgumentException();
+
+			this.n = n;
+		}
+
+		@Override
+		public void copyBlock(
+				final RandomAccess< T > in,
+				final RandomAccess< T > out,
+				final int[] dimensions )
+		{
+			if ( n == 3 )
+				copyBlock3D( out, dimensions[ 0 ], dimensions[ 1 ], dimensions[ 2 ], in );
+			else if ( n == 2 )
+				copyBlock2D( out, dimensions[ 0 ], dimensions[ 1 ], in );
+			else
+				copyBlock1D( out, dimensions[ 0 ], in );
+		}
+
+		private void copyBlock3D(
+				final RandomAccess< T > out,
+				final int sx, // size of output image
+				final int sy,
+				final int sz,
+				final RandomAccess< T > in )
+		{
+			for ( int z = 0; z < sz; ++z )
+			{
+				copyBlock2D( out, sx, sy, in );
+				out.fwd( 2 );
+				in.fwd( 2 );
+			}
+			out.move( -sz, 2 );
+			in.move( -sz, 2 );
+		}
+
+		private void copyBlock2D(
+				final RandomAccess< T > out,
+				final int sx, // size of output image
+				final int sy,
+				final RandomAccess< T > in )
+		{
+			for ( int y = 0; y < sy; ++y )
+			{
+				copyBlock1D( out, sx, in );
+				out.fwd( 1 );
+				in.fwd( 1 );
+			}
+			out.move( -sy, 1 );
+			in.move( -sy, 1 );
+		}
+
+		private void copyBlock1D(
+				final RandomAccess< T > out,
+				final int sx, // size of output image
+				final RandomAccess< T > in )
+		{
+			for ( int x = 0; x < sx; ++x )
+			{
+				out.get().set( in.get() );
+				out.fwd( 0 );
+				in.fwd( 0 );
+			}
+			out.move( -sx, 0 );
+			in.move( -sx, 0 );
+		}
+	}
+}

src/main/java/bdv/export/Downsample.java

 /*
  * #%L
- * BigDataViewer core classes with minimal dependencies
+ * BigDataViewer core classes with minimal dependencies.
  * %%
- * Copyright (C) 2012 - 2016 Tobias Pietzsch, Stephan Saalfeld, Stephan Preibisch,
- * Jean-Yves Tinevez, HongKee Moon, Johannes Schindelin, Curtis Rueden, John Bogovic
+ * Copyright (C) 2012 - 2020 BigDataViewer developers.
  * %%
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -44,6 +43,9 @@ import net.imglib2.view.Views;
 
 public class Downsample
 {
+	/**
+	 * TODO: Revise. This is probably not very efficient
+	 */
 	public static < T extends RealType< T > > void downsample( final RandomAccessible< T > input, final RandomAccessibleInterval< T > output, final int[] factor )
 	{
 		assert input.numDimensions() == output.numDimensions();