Merge remote-tracking branch 'github/master'

core/src/main/java/bdv/img/hdf5/Hdf5ImageLoader.java

@@ -7,6 +7,9 @@ import java.io.File;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 import mpicbg.spim.data.generic.sequence.AbstractSequenceDescription;
 import mpicbg.spim.data.generic.sequence.BasicViewSetup;
@@ -370,13 +373,55 @@ public class Hdf5ImageLoader extends AbstractViewerImgLoader< UnsignedShortType,
 		// copy unsigned short img to float img
 		final FloatType f = new FloatType();
 		final Img< FloatType > floatImg = net.imglib2.util.Util.getArrayOrCellImgFactory( ushortImg, f ).create( ushortImg, f );
-		final Cursor< UnsignedShortType > in = Views.iterable( ushortImg ).localizingCursor();
-		final RandomAccess< FloatType > out = floatImg.randomAccess();
-		while( in.hasNext() )
+
+		// set up executor service
+		final int numProcessors = Runtime.getRuntime().availableProcessors();
+		final ExecutorService taskExecutor = Executors.newFixedThreadPool( numProcessors );
+		final ArrayList< Callable< Boolean > > tasks = new ArrayList< Callable< Boolean > >();
+
+		// set up all threads
+		final int numPortions = numProcessors * 2;
+		final long threadChunkSize = floatImg.size() / numPortions;
+		final long threadChunkMod = floatImg.size() % numPortions;
+
+		for ( int portionID = 0; portionID < numPortions; ++portionID )
+		{
+			// move to the starting position of the current thread
+			final long startPosition = portionID * threadChunkSize;
+
+			// the last thread may has to run longer if the number of pixels cannot be divided by the number of threads
+			final long loopSize = ( portionID == numPortions - 1 ) ? threadChunkSize + threadChunkMod : threadChunkSize;
+
+			tasks.add( new Callable< Boolean >()
+			{
+				@Override
+				public Boolean call() throws Exception
+				{
+					final Cursor< UnsignedShortType > in = Views.iterable( ushortImg ).localizingCursor();
+					final RandomAccess< FloatType > out = floatImg.randomAccess();
+					
+					in.jumpFwd( startPosition );
+					
+					for ( long j = 0; j < loopSize; ++j )
+					{
+						final UnsignedShortType vin = in.next();
+						out.setPosition( in );
+						out.get().set( vin.getRealFloat() );
+					}
+					
+					return true;
+				}
+			});
+		}
+
+		try
+		{
+			// invokeAll() returns when all tasks are complete
+			taskExecutor.invokeAll( tasks );
+		}
+		catch ( final InterruptedException e )
 		{
-			in.next();
-			out.setPosition( in );
-			out.get().set( in.get().getRealFloat() );
+			return null;
 		}
 
 		if ( normalize )