diff --git a/IO/IOSS/Testing/Cxx/CMakeLists.txt b/IO/IOSS/Testing/Cxx/CMakeLists.txt
index 6efb9f0eeedbb0177aa64b5ec71f602c8bf0134b..cbba4612e8492d424262f52a4b183d0f1a304973 100644
--- a/IO/IOSS/Testing/Cxx/CMakeLists.txt
+++ b/IO/IOSS/Testing/Cxx/CMakeLists.txt
@@ -5,7 +5,7 @@ vtk_add_test_cxx(vtkIOIOSSCxxTests tests
   TestIOSSCGNS.cxx
   TestIOSSExodus.cxx,NO_VALID
   TestIOSSExodusMergeEntityBlocks.cxx,NO_VALID
-  TestIOSSExodusParallelWriter.cxx,
+  TestIOSSExodusParallelWriter.cxx
   TestIOSSExodusRestarts.cxx,NO_VALID
   TestIOSSExodusSetArrays.cxx
   TestIOSSExodusWriterCrinkleClip.cxx
diff --git a/IO/IOSS/Testing/Cxx/TestIOSSExodusParallelWriter.cxx b/IO/IOSS/Testing/Cxx/TestIOSSExodusParallelWriter.cxx
index ea1eb34fac0a876d0215f005a683a997dbe24e28..4d327a1b100dd367194b48fc951893e29c31eaeb 100644
--- a/IO/IOSS/Testing/Cxx/TestIOSSExodusParallelWriter.cxx
+++ b/IO/IOSS/Testing/Cxx/TestIOSSExodusParallelWriter.cxx
@@ -21,12 +21,12 @@
 #include <vtkRenderWindow.h>
 #include <vtkRenderWindowInteractor.h>
 #include <vtkRenderer.h>
-#include <vtkSynchronizedRenderWindows.h>
 #include <vtkTableBasedClipDataSet.h>
 #include <vtkTestUtilities.h>
 
 #if VTK_MODULE_ENABLE_VTK_ParallelMPI
 #include <vtkMPIController.h>
+#include <vtkSynchronizedRenderWindows.h>
 #else
 #include "vtkDummyController.h"
 #endif
@@ -155,10 +155,12 @@ int TestIOSSExodusParallelWriter(int argc, char* argv[])
   ren->ResetCamera(bds);
   ren->ResetCameraClippingRange(bds);
 
+#if VTK_MODULE_ENABLE_VTK_ParallelMPI
   vtkNew<vtkSynchronizedRenderWindows> syncWindows;
   syncWindows->SetRenderWindow(renWin);
   syncWindows->SetParallelController(contr);
   syncWindows->SetIdentifier(1);
+#endif
 
   vtkNew<vtkCompositedSynchronizedRenderers> syncRenderers;
   syncRenderers->SetRenderer(ren);
diff --git a/Imaging/Core/vtkImageSSIM.cxx b/Imaging/Core/vtkImageSSIM.cxx
index 6f8ba9a079f41ee03210da39833c14b0734560a5..8c695784b615d9d73da7b1f6468161f0b0dc846f 100644
--- a/Imaging/Core/vtkImageSSIM.cxx
+++ b/Imaging/Core/vtkImageSSIM.cxx
@@ -172,13 +172,16 @@ std::array<double, 3> ComputeMinkowski(vtkDoubleArray* array, double (*f)(double
   {
     for (int dim = 0; dim < 3; ++dim)
     {
+      // The range of ssim values is [-1, 1]. By doing 1 - value, we change the range to [0, 2]
       measure[dim] += f(1.0 - lab[dim]);
     }
   }
 
+  // Normalize the measure
+  const vtkIdType div = array->GetNumberOfTuples();
   for (int dim = 0; dim < 3; ++dim)
   {
-    measure[dim] /= array->GetNumberOfTuples();
+    measure[dim] /= div;
   }
 
   return measure;
@@ -186,13 +189,14 @@ std::array<double, 3> ComputeMinkowski(vtkDoubleArray* array, double (*f)(double
 
 std::array<double, 3> ComputeMinkowski1(vtkDoubleArray* array)
 {
-  return ComputeMinkowski(array, &std::abs);
+  auto same = [](double v) -> double { return v; };
+  return ComputeMinkowski(array, same);
 }
 
 std::array<double, 3> ComputeMinkowski2(vtkDoubleArray* array)
 {
-  auto f = [](double v) { return v * v; };
-  auto measure = ComputeMinkowski(array, f);
+  auto power2 = [](double v) -> double { return v * v; };
+  auto measure = ComputeMinkowski(array, power2);
   for (int dim = 0; dim < 3; ++dim)
   {
     measure[dim] = std::sqrt(measure[dim]);
@@ -200,34 +204,47 @@ std::array<double, 3> ComputeMinkowski2(vtkDoubleArray* array)
   return measure;
 }
 
-std::array<double, 3> ComputeWasserstein(vtkDoubleArray* array, double (*f)(double))
+std::array<double, 3> ComputeWasserstein(vtkDoubleArray* array, std::uint64_t (*f)(std::uint64_t))
 {
   std::array<double, 3> measure = {};
 
   auto data = vtk::DataArrayTupleRange<3>(array);
 
-  constexpr int N = 100;
-  std::array<double, N> hist[3] = {};
+  constexpr std::uint64_t N = 200;
+  std::array<std::uint64_t, N> hist[3] = {};
 
   for (auto lab : data)
   {
     for (int dim = 0; dim < 3; ++dim)
     {
-      ++hist[dim][std::round(lab[dim] * (N - 1))];
+      // The range of ssim values is [-1, 1], so we rescale it to [0, 1]
+      double value = (lab[dim] + 1.0) / 2.0;
+      // Find the bucket to place the value in, by rescaling it to [0, N - 1]
+      // [0, (N - 1) / 2] is for negative ssim values,
+      // N / 2 is for ssim = 0,
+      // ((N + 1) / 2, N - 1] is for positive ssim values
+      auto bucket = static_cast<std::uint32_t>(std::round(value * (N - 1)));
+      ++hist[dim][bucket];
     }
   }
 
   for (int dim = 0; dim < 3; ++dim)
   {
-    std::array<double, N> cfd;
+    // Compute the cumulative frequency distribution
+    std::array<std::uint64_t, N> cfd;
     std::partial_sum(hist[dim].begin(), hist[dim].end(), cfd.begin());
 
     for (std::size_t i = 0; i < N - 1; ++i)
     {
       measure[dim] += f(cfd[i]);
     }
+  }
 
-    measure[dim] += f(cfd.back() - array->GetNumberOfTuples());
+  // Normalize the measure
+  const vtkIdType div = f(static_cast<std::uint64_t>(array->GetNumberOfTuples())) * (N - 1);
+  for (int dim = 0; dim < 3; ++dim)
+  {
+    measure[dim] /= div;
   }
 
   return measure;
@@ -235,23 +252,16 @@ std::array<double, 3> ComputeWasserstein(vtkDoubleArray* array, double (*f)(doub
 
 std::array<double, 3> ComputeWasserstein1(vtkDoubleArray* array)
 {
-  auto measure = ComputeWasserstein(array, &std::abs);
-  vtkIdType div = array->GetNumberOfTuples() * (100 - 1);
-  for (int dim = 0; dim < 3; ++dim)
-  {
-    measure[dim] /= div;
-  }
-  return measure;
+  auto same = [](std::uint64_t v) -> std::uint64_t { return v; };
+  return ComputeWasserstein(array, same);
 }
 
 std::array<double, 3> ComputeWasserstein2(vtkDoubleArray* array)
 {
-  auto f = [](double v) { return v * v; };
-  auto measure = ComputeWasserstein(array, f);
-  vtkIdType div = array->GetNumberOfTuples() * array->GetNumberOfTuples() * (100 - 1);
+  auto power2 = [](std::uint64_t v) -> std::uint64_t { return v * v; };
+  auto measure = ComputeWasserstein(array, power2);
   for (int dim = 0; dim < 3; ++dim)
   {
-    measure[dim] /= div;
     measure[dim] = std::sqrt(measure[dim]);
   }
   return measure;
@@ -259,7 +269,7 @@ std::array<double, 3> ComputeWasserstein2(vtkDoubleArray* array)
 } // anonymous namespace
 
 //------------------------------------------------------------------------------
-// Construct object to extract all of the input data.
+// Construct object to extract all the input data.
 vtkImageSSIM::vtkImageSSIM()
 {
   this->SetNumberOfInputPorts(2);
diff --git a/Testing/Rendering/vtkTesting.cxx b/Testing/Rendering/vtkTesting.cxx
index 1d26ae0ec46169386666c5e8d0bc16e43a00a264..f396a15952badb49826524a8c02add547d0d6ca7 100644
--- a/Testing/Rendering/vtkTesting.cxx
+++ b/Testing/Rendering/vtkTesting.cxx
@@ -845,7 +845,8 @@ int vtkTesting::RegressionTest(vtkAlgorithm* imageSource, double thresh, ostream
     vtkEmscriptenTestUtilities::PreloadDataFile(hostFileName.c_str(), sandboxedFileName);
     // so that subsequent code uses the sandboxed file name instead of host file name.
     delete[] newFileName;
-    newFileName = strdup(sandboxedFileName.c_str());
+    newFileName = new char[sandboxedFileName.size() + 1];
+    strcpy(newFileName, sandboxedFileName.c_str());
 #endif
     if (!LookForFile(newFileName))
     {
@@ -866,7 +867,7 @@ int vtkTesting::RegressionTest(vtkAlgorithm* imageSource, double thresh, ostream
     if ((ext2[1] - ext2[0]) == (ext1[1] - ext1[0]) && (ext2[3] - ext2[2]) == (ext1[3] - ext1[2]) &&
       (ext2[5] - ext2[4]) == (ext1[5] - ext1[4]))
     {
-      vtkLog(INFO, "Trying onother baseline.");
+      vtkLog(INFO, "Trying another baseline.");
       // Cannot compute difference unless image sizes are the same
       executeComparison(error);
     }
@@ -972,7 +973,8 @@ int vtkTesting::RegressionTest(vtkAlgorithm* imageSource, double thresh, ostream
 #ifdef __EMSCRIPTEN__
     std::string sandboxedFileName = vtkEmscriptenTestUtilities::PreloadDataFile(newFileName);
     delete[] newFileName;
-    newFileName = strdup(sandboxedFileName.c_str());
+    newFileName = new char[sandboxedFileName.size() + 1];
+    strcpy(newFileName, sandboxedFileName.c_str());
 #endif
     rtPng->SetFileName(newFileName);
     delete[] newFileName;