COMP: Harden streaming-equivalence tests with upstream CastImageFilter

Modules/Filtering/ImageGrid/test/itkResampleImageTest7.cxx

@@ -19,6 +19,8 @@
 #include <iostream>
 
 #include "itkAffineTransform.h"
+#include "itkCastImageFilter.h"
+#include "itkPipelineMonitorImageFilter.h"
 #include "itkResampleImageFilter.h"
 #include "itkStreamingImageFilter.h"
 #include "itkTestingMacros.h"
@@ -79,8 +81,17 @@ itkResampleImageTest7(int, char *[])
   ITK_EXERCISE_BASIC_OBJECT_METHODS(resample, ResampleImageFilter, ImageToImageFilter);
   resample->SetInterpolator(interp);
 
-  resample->SetInput(image);
-  ITK_TEST_SET_GET_VALUE(image.GetPointer(), resample->GetInput());
+  // Route the input through CastImageFilter so the streaming-equivalence comparison
+  // exercises a chunked BufferedRegion, which an in-memory Image alone cannot produce.
+  // PipelineMonitorImageFilter then records each chunked Update so we can assert the
+  // filter under test actually saw N executions when streaming requests N divisions.
+  const auto upstream = itk::CastImageFilter<ImageType, ImageType>::New();
+  upstream->SetInput(image);
+  using MonitorType = itk::PipelineMonitorImageFilter<ImageType>;
+  const auto monitor = MonitorType::New();
+  monitor->SetInput(upstream->GetOutput());
+  resample->SetInput(monitor->GetOutput());
+  ITK_TEST_SET_GET_VALUE(monitor->GetOutput(), resample->GetInput());
 
   resample->SetSize(size);
   ITK_TEST_SET_GET_VALUE(size, resample->GetSize());
@@ -109,12 +120,24 @@ itkResampleImageTest7(int, char *[])
   const ImagePointerType outputNoSDI = streamer->GetOutput(); // save output for later comparison
   outputNoSDI->DisconnectPipeline();                          // disconnect to create new output
 
+  // Reset the streaming history before the streamed pass so the verify below
+  // sees only the streamed run's chunks.
+  monitor->ClearPipelineSavedInformation();
+
   // Run the resampling filter with streaming
   image->Modified();
   numStreamDiv = 8; // split into numStream pieces for streaming.
   streamer->SetNumberOfStreamDivisions(numStreamDiv);
   ITK_TRY_EXPECT_NO_EXCEPTION(streamer->UpdateLargestPossibleRegion());
 
+  // Confirm the upstream chain actually streamed the requested number of chunks.
+  if (!monitor->VerifyInputFilterExecutedStreaming(static_cast<int>(numStreamDiv)))
+  {
+    std::cerr << "Streaming did not chunk the input as expected." << std::endl;
+    std::cerr << monitor;
+    return EXIT_FAILURE;
+  }
+
   // Verify that we only requested a smaller chunk when streaming
   const ImageRegionType finalRequestedRegion(image->GetRequestedRegion());
   ITK_TEST_SET_GET_VALUE(0, finalRequestedRegion.GetIndex(0));

Modules/Filtering/ImageGrid/test/itkWarpImageFilterTest.cxx

@@ -21,6 +21,7 @@
 #include "itkMath.h"
 #include "itkWarpImageFilter.h"
 #include "itkCastImageFilter.h"
+#include "itkPipelineMonitorImageFilter.h"
 #include "itkStreamingImageFilter.h"
 #include "itkVectorImage.h"
 #include "itkTestingMacros.h"
@@ -318,23 +319,40 @@ itkWarpImageFilterTest(int, char *[])
 
   std::cout << "Run ExpandImageFilter with streamer" << std::endl;
 
+  // Route the displacement field through a CastImageFilter (streaming-aware no-op)
+  // and a PipelineMonitorImageFilter so we can assert the warper actually streamed
+  // its displacement-field input.  The image input is intentionally NOT routed
+  // through a similar chain: WarpImageFilter requests its full image input for any
+  // output region, so verifying streaming on the image input would always fail.
   using VectorCasterType = itk::CastImageFilter<FieldType, FieldType>;
   auto vcaster = VectorCasterType::New();
-
   vcaster->SetInput(warper->GetDisplacementField());
 
+  using FieldMonitorType = itk::PipelineMonitorImageFilter<FieldType>;
+  auto vmonitor = FieldMonitorType::New();
+  vmonitor->SetInput(vcaster->GetOutput());
+
   auto warper2 = WarperType::New();
 
   warper2->SetInput(warper->GetInput());
-  warper2->SetDisplacementField(vcaster->GetOutput());
+  warper2->SetDisplacementField(vmonitor->GetOutput());
   warper2->SetEdgePaddingValue(warper->GetEdgePaddingValue());
 
   using StreamerType = itk::StreamingImageFilter<ImageType, ImageType>;
   auto streamer = StreamerType::New();
   streamer->SetInput(warper2->GetOutput());
-  streamer->SetNumberOfStreamDivisions(3);
+  constexpr int numStreamDivisions = 3;
+  streamer->SetNumberOfStreamDivisions(numStreamDivisions);
   streamer->Update();
 
+  // Confirm the warp actually streamed its displacement-field input.
+  if (!vmonitor->VerifyInputFilterExecutedStreaming(numStreamDivisions))
+  {
+    std::cerr << "Displacement field did not stream as expected." << std::endl;
+    std::cerr << vmonitor;
+    return EXIT_FAILURE;
+  }
+
   std::cout << "Compare standalone and streamed outputs" << std::endl;
 
   Iterator streamIter(streamer->GetOutput(), streamer->GetOutput()->GetBufferedRegion());

Modules/Filtering/ImageGrid/test/itkWarpVectorImageFilterTest.cxx

@@ -20,6 +20,7 @@
 
 #include "itkWarpVectorImageFilter.h"
 #include "itkCastImageFilter.h"
+#include "itkPipelineMonitorImageFilter.h"
 #include "itkStreamingImageFilter.h"
 #include "itkTestingMacros.h"
 
@@ -297,18 +298,35 @@ itkWarpVectorImageFilterTest(int, char *[])
 
   vcaster->SetInput(warper->GetDisplacementField());
 
+  // PipelineMonitorImageFilter on the displacement-field path so we can assert
+  // the warper actually streamed that input.  WarpVectorImageFilter requests its
+  // full image input for any output region, so verifying streaming on the image
+  // input would always fail.
+  using FieldMonitorType = itk::PipelineMonitorImageFilter<FieldType>;
+  auto vmonitor = FieldMonitorType::New();
+  vmonitor->SetInput(vcaster->GetOutput());
+
   auto warper2 = WarperType::New();
 
   warper2->SetInput(warper->GetInput());
-  warper2->SetDisplacementField(vcaster->GetOutput());
+  warper2->SetDisplacementField(vmonitor->GetOutput());
   warper2->SetEdgePaddingValue(warper->GetEdgePaddingValue());
 
   using StreamerType = itk::StreamingImageFilter<ImageType, ImageType>;
   auto streamer = StreamerType::New();
   streamer->SetInput(warper2->GetOutput());
-  streamer->SetNumberOfStreamDivisions(3);
+  constexpr int numStreamDivisions = 3;
+  streamer->SetNumberOfStreamDivisions(numStreamDivisions);
   streamer->Update();
 
+  // Confirm the warp actually streamed its displacement-field input.
+  if (!vmonitor->VerifyInputFilterExecutedStreaming(numStreamDivisions))
+  {
+    std::cerr << "Displacement field did not stream as expected." << std::endl;
+    std::cerr << vmonitor;
+    return EXIT_FAILURE;
+  }
+
   std::cout << "Compare standalone and streamed outputs" << std::endl;
 
   Iterator streamIter(streamer->GetOutput(), streamer->GetOutput()->GetBufferedRegion());