Adding a vtkImageDifference test

Imaging/Core/Testing/CMakeLists.txt

@@ -1,4 +1,6 @@
 vtk_module_test_data(
+  Data/ImageDiff1.png
+  Data/ImageDiff2.png
   Data/beach.tif
   Data/fullhead15.png
   Data/headsq/,REGEX:.*)

Imaging/Core/Testing/Cxx/CMakeLists.txt

@@ -4,6 +4,7 @@ vtk_add_test_cxx(vtkImagingCoreCxxTests tests
   ImageAccumulateLarge.cxx,NO_VALID,NO_DATA,NO_OUTPUT 32
   ImageAutoRange.cxx
   ImageBSplineCoefficients.cxx
+  ImageDifference.cxx,NO_VALID
   ImageGenericInterpolateSlidingWindow3D.cxx
   ImageHistogram.cxx
   ImageHistogramStatistics.cxx,NO_VALID

Imaging/Core/Testing/Cxx/ImageDifference.cxx

@@ -0,0 +1,142 @@
+/*=========================================================================
+
+  Program:   Visualization Toolkit
+  Module:    ImageDifference.cxx
+
+  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
+  All rights reserved.
+  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+     PURPOSE.  See the above copyright notice for more information.
+
+=========================================================================*/
+// Test the vtkImageDifference class
+
+#include "vtkImageDifference.h"
+#include "vtkMathUtilities.h"
+#include "vtkNew.h"
+#include "vtkPNGReader.h"
+#include "vtkTestUtilities.h"
+
+#include <iostream>
+#include <limits>
+
+namespace
+{
+bool CheckErrors(vtkImageDifference* differenceFilter, double expectedError,
+  double expectedThresholdedError, const std::string& info)
+{
+  if (!vtkMathUtilities::FuzzyCompare(differenceFilter->GetError(), expectedError, 1e-8) ||
+    !vtkMathUtilities::FuzzyCompare(
+      differenceFilter->GetThresholdedError(), expectedThresholdedError, 1e-8))
+  {
+    std::cerr << std::setprecision(std::numeric_limits<double>::digits10);
+    std::cerr << std::setprecision(17);
+    std::cerr << "Unexpected vtkImageDifference errors with " << info << std::endl;
+    std::cerr << "Expected error: " << expectedError << ", got: " << differenceFilter->GetError()
+              << " " << (expectedError != differenceFilter->GetError()) << std::endl;
+    std::cerr << "Expected thresholded error: " << expectedThresholdedError
+              << ", got: " << differenceFilter->GetThresholdedError() << " "
+              << (expectedThresholdedError != differenceFilter->GetThresholdedError()) << std::endl;
+    return false;
+  }
+  return true;
+}
+}
+
+int ImageDifference(int argc, char* argv[])
+{
+  char* fname1 = vtkTestUtilities::ExpandDataFileName(argc, argv, "Data/ImageDiff1.png");
+  char* fname2 = vtkTestUtilities::ExpandDataFileName(argc, argv, "Data/ImageDiff2.png");
+
+  vtkNew<vtkPNGReader> reader1;
+  reader1->SetFileName(fname1);
+  reader1->Update();
+
+  vtkNew<vtkPNGReader> reader2;
+  reader2->SetFileName(fname2);
+  reader2->Update();
+
+  delete[] fname1;
+  delete[] fname2;
+
+  vtkNew<vtkImageDifference> differenceFilter;
+  differenceFilter->SetInputConnection(reader1->GetOutputPort());
+  differenceFilter->SetImageConnection(reader2->GetOutputPort());
+
+  // Default param
+  differenceFilter->Update();
+  if (!::CheckErrors(
+        differenceFilter, 10600.898039215839, 0.97124183006535825, "default parameters"))
+  {
+    return EXIT_FAILURE;
+  }
+
+  // Testing symmetric
+  differenceFilter->SetInputConnection(reader2->GetOutputPort());
+  differenceFilter->SetImageConnection(reader1->GetOutputPort());
+  differenceFilter->Update();
+  if (!::CheckErrors(
+        differenceFilter, 10600.898039215839, 0.97124183006535825, "symmetric testing"))
+  {
+    return EXIT_FAILURE;
+  }
+
+  // Zero threshold
+  differenceFilter->SetThreshold(0);
+  differenceFilter->Update();
+  if (!::CheckErrors(differenceFilter, 9342.9607843138092, 9342.9607843138092, "zero threshold"))
+  {
+    return EXIT_FAILURE;
+  }
+
+  // Higher average threshold
+  differenceFilter->SetThreshold(105);
+  differenceFilter->SetAverageThresholdFactor(1.);
+  differenceFilter->Update();
+  if (!::CheckErrors(
+        differenceFilter, 10594.431372549172, 0.22614379084967323, "higher average threshold"))
+  {
+    return EXIT_FAILURE;
+  }
+
+  // No averaging
+  differenceFilter->SetAverageThresholdFactor(0.5);
+  differenceFilter->SetAveraging(false);
+  differenceFilter->Update();
+  if (!::CheckErrors(differenceFilter, 10600.898039215839, 0.97124183006535825, "no averaging"))
+  {
+    return EXIT_FAILURE;
+  }
+
+  // No shift
+  differenceFilter->SetAveraging(true);
+  differenceFilter->SetAllowShift(false);
+  differenceFilter->Update();
+  if (!::CheckErrors(differenceFilter, 9587.1254901961565, 1.1986928104575143, "no shift"))
+  {
+    return EXIT_FAILURE;
+  }
+
+  // Multi param
+  differenceFilter->SetThreshold(0);
+  differenceFilter->SetAveraging(false);
+  differenceFilter->Update();
+  if (!::CheckErrors(
+        differenceFilter, 9587.1254901961565, 9587.1254901961565, "multiple parameters changes"))
+  {
+    return EXIT_FAILURE;
+  }
+
+  // Identical
+  differenceFilter->SetInputConnection(reader1->GetOutputPort());
+  differenceFilter->Update();
+  if (!::CheckErrors(differenceFilter, 0., 0., "identical images"))
+  {
+    return EXIT_FAILURE;
+  }
+
+  return EXIT_SUCCESS;
+}

Testing/Data/ImageDiff1.png.sha512

@@ -0,0 +1 @@
+d433e15a7e9bfb3b03eb5b5c73d3956782fd1f5662008ceb5180600202c87e4c47e541c4409c1bca5a6083183f3a005aeb70155c218a9977478ae9900d773963

Testing/Data/ImageDiff2.png.sha512

@@ -0,0 +1 @@
+2f6bf435136d567d6f9a4199f657073002f39d6c83dafac64223f6f6bb8d3af13cfe8c43f2e781695caff1f13019e02f58007f4d042c85c0eee3211f38758ce8