Use multithreading with neighborhood Ops

elevans · elevans · commit 83ee3c4a54eb · 2025-02-06T13:21:31.000-06:00
Without multi-threading an image operated on with a neighborhood Op
takes extremely long to compute. For example, take an input image
with shape (512, 512, 256) and dtype. Using a RectangleShape
neighborhood with a span size of 4, keeping the center, and the
"filter.median" Op takes a shocking 1521.778 seconds or 25.36
minutes to complete. With multi-threading added the compute time goes
down to 496.36 seconds or 8.27 minutes.

[PC specs]
OS: Debian Bookworm 12.9 x86_64
CPU: 11th Gen Intel(R) Core(TM) i7-1185G7 (8) @ 4.80 GHz
RAM: 32 GB
diff --git a/scijava-ops-image/src/main/java/org/scijava/ops/image/adapt/LiftNeighborhoodComputersToRAI.java b/scijava-ops-image/src/main/java/org/scijava/ops/image/adapt/LiftNeighborhoodComputersToRAI.java
@@ -60,7 +60,7 @@ private LiftNeighborhoodComputersToRAI() {
 			var extended = Views.extend(in, oobf);
 			var neighborhoods = shape.neighborhoodsRandomAccessible(extended);
 			var intervaled = Views.interval(neighborhoods, in);
-			LoopBuilder.setImages(intervaled, out).forEachPixel(op);
+			LoopBuilder.setImages(intervaled, out).multiThreaded().forEachPixel(op);
 		};
 	}
 
@@ -77,7 +77,7 @@ private LiftNeighborhoodComputersToRAI() {
 			var extended = Views.extend(in, oobf);
 			var neighborhoods = shape.neighborhoodsRandomAccessible(extended);
 			var intervaled = Views.interval(neighborhoods, in);
-			LoopBuilder.setImages(intervaled, out).forEachPixel(op);
+			LoopBuilder.setImages(intervaled, out).multiThreaded().forEachPixel(op);
 		};
 	}
 
@@ -97,7 +97,7 @@ private LiftNeighborhoodComputersToRAI() {
 			var extended = Views.extend(in1, oobf);
 			var neighborhoods = shape.neighborhoodsRandomAccessible(extended);
 			var intervaled = Views.interval(neighborhoods, in1);
-			LoopBuilder.setImages(intervaled, out).forEachPixel((in, container) -> op
+			LoopBuilder.setImages(intervaled, out).multiThreaded().forEachPixel((in, container) -> op
 				.compute(in, in2, container));
 		};
 	}
@@ -115,7 +115,7 @@ private LiftNeighborhoodComputersToRAI() {
 			var extended = Views.extend(in1, oobf);
 			var neighborhoods = shape.neighborhoodsRandomAccessible(extended);
 			var intervaled = Views.interval(neighborhoods, in1);
-			LoopBuilder.setImages(intervaled, out).forEachPixel((in, container) -> op
+			LoopBuilder.setImages(intervaled, out).multiThreaded().forEachPixel((in, container) -> op
 				.compute(in, in2, container));
 		};
 	}
@@ -136,7 +136,7 @@ private LiftNeighborhoodComputersToRAI() {
 			var extended = Views.extend(in1, oobf);
 			var neighborhoods = shape.neighborhoodsRandomAccessible(extended);
 			var intervaled = Views.interval(neighborhoods, in1);
-			LoopBuilder.setImages(intervaled, out).forEachPixel((in, container) -> op
+			LoopBuilder.setImages(intervaled, out).multiThreaded().forEachPixel((in, container) -> op
 				.compute(in, in2, in3, container));
 		};
 	}
@@ -154,7 +154,7 @@ private LiftNeighborhoodComputersToRAI() {
 			var extended = Views.extend(in1, oobf);
 			var neighborhoods = shape.neighborhoodsRandomAccessible(extended);
 			var intervaled = Views.interval(neighborhoods, in1);
-			LoopBuilder.setImages(intervaled, out).forEachPixel((in, container) -> op
+			LoopBuilder.setImages(intervaled, out).multiThreaded().forEachPixel((in, container) -> op
 				.compute(in, in2, in3, container));
 		};
 	}
