FIX: Verification Test

Change the test to blur CTChest. The reference output was generated with itk::DiscreteGaussianImageFilter directly, so the Halide output is verified to be numerically compatible.

test/CMakeLists.txt

@@ -6,11 +6,14 @@ set(HalideFiltersTests
 
 CreateTestDriver(HalideFilters "${HalideFilters-Test_LIBRARIES}" "${HalideFiltersTests}")
 
+# NOTE: Input data is CTChest Slicer sample data: anisotropic image with blur variance 9mm.
+# Reference output generated with itk::DiscreteGaussianImageFilter (via Slicer Simple Filters).
 itk_add_test(NAME itkHalideDiscreteGaussianImageFilterTest
-  COMMAND HalideFiltersTestDriver
-    --compare
-    DATA{Baseline/itkHalideDiscreteGaussianImageFilterTestOutput.mha}
-    ${ITK_TEST_OUTPUT_DIR}/itkHalideDiscreteGaussianImageFilterTestOutput.mha
+  COMMAND
+  HalideFiltersTestDriver
+  --compare DATA{CTChest/ReferenceOutput.mha} ${ITK_TEST_OUTPUT_DIR}/Output.mha
   itkHalideDiscreteGaussianImageFilterTest
-    ${ITK_TEST_OUTPUT_DIR}/itkHalideDiscreteGaussianImageFilterTestOutput.mha
+  DATA{CTChest/Input.mha}
+  ${ITK_TEST_OUTPUT_DIR}/Output.mha
+  9
   )

test/CTChest/Input.mha.sha512

@@ -0,0 +1 @@
+813f7605a1bbc3c6cd3405cf7231b9c3eb8b3e2102ad64294b8e7349989111cafd5cf47d367e488cebde2eab50f1a19b21d8327f8f8d8b42caf579cc2f645bd0

test/CTChest/ReferenceOutput.mha.sha512

@@ -0,0 +1 @@
+6c9594313ea163d3b5f3d808fd1f1cd34b8073cb8d028056d58b6f1bf24ae5aef3a232b1a71cec5e6e0d062ffc16e36df8527c95be51d70c0dbce49da44c87ff

test/itkHalideDiscreteGaussianImageFilterTest.cxx

@@ -20,6 +20,7 @@
 
 #include "itkCommand.h"
 #include "itkImageFileWriter.h"
+#include "itkImageFileReader.h"
 #include "itkTestingMacros.h"
 
 namespace
@@ -55,15 +56,21 @@ class ShowProgress : public itk::Command
 int
 itkHalideDiscreteGaussianImageFilterTest(int argc, char * argv[])
 {
-  if (argc < 2)
+  if (argc < 4)
   {
     std::cerr << "Missing parameters." << std::endl;
     std::cerr << "Usage: " << itkNameOfTestExecutableMacro(argv);
+    std::cerr << " inputImage";
     std::cerr << " outputImage";
+    std::cerr << " variance";
     std::cerr << std::endl;
     return EXIT_FAILURE;
   }
-  const char * outputImageFileName = argv[1];
+  const char * inputImageFileName = argv[1];
+  const char * outputImageFileName = argv[2];
+  const char * varianceString = argv[3];
+
+  float variance = std::stof(varianceString);
 
   constexpr unsigned int Dimension = 3;
   using PixelType = float;
@@ -74,18 +81,15 @@ itkHalideDiscreteGaussianImageFilterTest(int argc, char * argv[])
 
   ITK_EXERCISE_BASIC_OBJECT_METHODS(filter, HalideDiscreteGaussianImageFilter, ImageToImageFilter);
 
-  // Create input image to avoid test dependencies.
-  ImageType::SizeType size;
-  size.Fill(128);
-  ImageType::Pointer image = ImageType::New();
-  image->SetRegions(size);
-  image->Allocate();
-  image->FillBuffer(1.1f);
+  using ReaderType = itk::ImageFileReader<ImageType>;
+  ReaderType::Pointer reader = ReaderType::New();
+  reader->SetFileName(inputImageFileName);
+  reader->Update();
 
   ShowProgress::Pointer showProgress = ShowProgress::New();
   filter->AddObserver(itk::ProgressEvent(), showProgress);
-  filter->SetInput(image);
-  filter->SetSigma(2);
+  filter->SetInput(reader->GetOutput());
+  filter->SetVariance(variance);
 
   using WriterType = itk::ImageFileWriter<ImageType>;
   WriterType::Pointer writer = WriterType::New();