Deprecate ImageConstIterator::GetIndex(), use ComputeIndex() in tests and examples

Documentation/docs/migration_guides/itk_6_migration_guide.md

@@ -172,6 +172,15 @@ reoriented_image = itk.orient_image_filter(
 )
 ```
 
+`GetIndex()` replaced with `ComputeIndex()`, for iterators without index
+------------------------------------------------------------------------
+`ImageConstIterator::GetIndex()` is marked to be removed in the future. This iterator does not have an index,
+internally, so its `GetIndex()` member function does a potentially expensive computation. For an iterator that is
+derived from `ImageConstIterator`, please use its newly introduced `ComputeIndex()` member function instead. Or use an
+iterator _with_ index (like `ImageIteratorWithIndex`).
+
+
+
 Remove support for Python wrapped `long double` types
 -----------------------------------------------------
 

Examples/DataRepresentation/Mesh/ImageToPointSet.cxx

@@ -88,7 +88,7 @@ main(int argc, char * argv[])
   {
 
     // Convert the pixel position into a Point
-    image->TransformIndexToPhysicalPoint(it.GetIndex(), point);
+    image->TransformIndexToPhysicalPoint(it.ComputeIndex(), point);
     pointSet->SetPoint(pointId, point);
 
     // Transfer the pixel data to the value associated with the point.

Examples/Filtering/GaussianBlurImageFunction.cxx

@@ -72,7 +72,7 @@ main(int argc, char * argv[])
 
   while (!it.IsAtEnd())
   {
-    out.Set(gaussianFunction->EvaluateAtIndex(it.GetIndex()));
+    out.Set(gaussianFunction->EvaluateAtIndex(it.ComputeIndex()));
     ++it;
     ++out;
   }

Examples/RegistrationITKv4/BSplineWarping1.cxx

@@ -334,7 +334,7 @@ main(int argc, char * argv[])
 
   while (!fi.IsAtEnd())
   {
-    index = fi.GetIndex();
+    index = fi.ComputeIndex();
     field->TransformIndexToPhysicalPoint(index, fixedPoint);
     movingPoint = bsplineTransform->TransformPoint(fixedPoint);
     displacement = movingPoint - fixedPoint;

Examples/RegistrationITKv4/BSplineWarping2.cxx

@@ -334,7 +334,7 @@ main(int argc, char * argv[])
 
   while (!fi.IsAtEnd())
   {
-    index = fi.GetIndex();
+    index = fi.ComputeIndex();
     field->TransformIndexToPhysicalPoint(index, fixedPoint);
     movingPoint = bsplineTransform->TransformPoint(fixedPoint);
     displacement = movingPoint - fixedPoint;

Examples/RegistrationITKv4/DeformableRegistration12.cxx

@@ -460,7 +460,7 @@ main(int argc, char * argv[])
 
     while (!fi.IsAtEnd())
     {
-      index = fi.GetIndex();
+      index = fi.ComputeIndex();
       field->TransformIndexToPhysicalPoint(index, fixedPoint);
       movingPoint = transform->TransformPoint(fixedPoint);
       displacement = movingPoint - fixedPoint;

Examples/RegistrationITKv4/DeformableRegistration13.cxx

@@ -449,7 +449,7 @@ main(int argc, char * argv[])
 
     while (!fi.IsAtEnd())
     {
-      index = fi.GetIndex();
+      index = fi.ComputeIndex();
       field->TransformIndexToPhysicalPoint(index, fixedPoint);
       movingPoint = transform->TransformPoint(fixedPoint);
       displacement = movingPoint - fixedPoint;

Examples/RegistrationITKv4/DeformableRegistration14.cxx

@@ -435,7 +435,7 @@ main(int argc, char * argv[])
 
     while (!fi.IsAtEnd())
     {
-      index = fi.GetIndex();
+      index = fi.ComputeIndex();
       field->TransformIndexToPhysicalPoint(index, fixedPoint);
       movingPoint = transform->TransformPoint(fixedPoint);
       displacement = movingPoint - fixedPoint;

Examples/RegistrationITKv4/DeformableRegistration15.cxx

@@ -836,7 +836,7 @@ main(int argc, char * argv[])
 
     while (!fi.IsAtEnd())
     {
-      index = fi.GetIndex();
+      index = fi.ComputeIndex();
       field->TransformIndexToPhysicalPoint(index, fixedPoint);
       movingPoint = bsplineTransformFine->TransformPoint(fixedPoint);
       displacement = movingPoint - fixedPoint;

Examples/RegistrationITKv4/ThinPlateSplineWarp.cxx

@@ -179,7 +179,7 @@ ExampleMain(int argc, const char * const argv[])
   FieldVectorType displacement;
   while (!fi.IsAtEnd())
   {
-    index = fi.GetIndex();
+    index = fi.ComputeIndex();
     field->TransformIndexToPhysicalPoint(index, point1);
     point2 = tps->TransformPoint(point1);
     for (unsigned int i = 0; i < ImageDimension; ++i)

Modules/Core/Common/include/itkImageConstIterator.h

@@ -303,15 +303,17 @@ class ITK_TEMPLATE_EXPORT ImageConstIterator
     return m_Image->ComputeIndex(m_Offset);
   }
 
+#ifndef ITK_FUTURE_LEGACY_REMOVE
   /** Computes and returns the index. This may be a relatively expensive operation.
-   * \note It is often preferable for users to call ComputeIndex() directly, to make it more clear that this function
-   * may be expensive.
-   * \sa ComputeIndex */
+   * \deprecated Please use `ComputeIndex()` instead, or use an iterator with index, like `ImageIteratorWithIndex`! */
+  ITK_FUTURE_DEPRECATED(
+    "Please use `ComputeIndex()` instead, or use an iterator with index, like `ImageIteratorWithIndex`!")
   [[nodiscard]] IndexType
   GetIndex() const
   {
     return this->ComputeIndex();
   }
+#endif
 
   /** Set the index. No bounds checking is performed.
    * \sa GetIndex */

Modules/Core/Common/test/itkConstNeighborhoodIteratorTest.cxx

@@ -314,7 +314,7 @@ itkConstNeighborhoodIteratorTest(int, char *[])
     // Set all pixels with first index == 0 to 0, and set the rest of the image to 255
     while (!createImageIterator.IsAtEnd())
     {
-      if (createImageIterator.GetIndex()[0] == 0)
+      if (createImageIterator.ComputeIndex()[0] == 0)
       {
         createImageIterator.Set(0);
       }

Modules/Core/Common/test/itkConstShapedNeighborhoodIteratorTest.cxx

@@ -421,7 +421,7 @@ itkConstShapedNeighborhoodIteratorTest(int, char *[])
     // Set all pixels with first index == 0 to 0, and set the rest of the image to 255
     while (!createImageIterator.IsAtEnd())
     {
-      if (createImageIterator.GetIndex()[0] == 0)
+      if (createImageIterator.ComputeIndex()[0] == 0)
       {
         createImageIterator.Set(0);
       }

Modules/Core/Common/test/itkExtractImageTest.cxx

@@ -176,8 +176,8 @@ itkExtractImageTest(int, char *[])
 
     for (; !iteratorIn1.IsAtEnd(); ++iteratorIn1)
     {
-      const ShortImage::IndexType::IndexValueType row = iteratorIn1.GetIndex()[0];
-      const ShortImage::IndexType::IndexValueType column = iteratorIn1.GetIndex()[1];
+      const ShortImage::IndexType::IndexValueType row = iteratorIn1.ComputeIndex()[0];
+      const ShortImage::IndexType::IndexValueType column = iteratorIn1.ComputeIndex()[1];
       if ((row < 0) || (row > 7) || (column < 0) || (column > 11))
       {
         if (iteratorIn1.Get() != 13)
@@ -251,8 +251,8 @@ itkExtractImageTest(int, char *[])
     {
       for (; !iteratorIn2.IsAtEnd(); ++iteratorIn2)
       {
-        const ShortImage::IndexType::IndexValueType row = iteratorIn2.GetIndex()[0];
-        const ShortImage::IndexType::IndexValueType column = iteratorIn2.GetIndex()[1];
+        const ShortImage::IndexType::IndexValueType row = iteratorIn2.ComputeIndex()[0];
+        const ShortImage::IndexType::IndexValueType column = iteratorIn2.ComputeIndex()[1];
         if ((row < 0) || (row > 7) || (column < 0) || (column > 11))
         {
           if (iteratorIn2.Get() != 13)
@@ -318,7 +318,7 @@ itkExtractImageTest(int, char *[])
   {
     const LineImage::PixelType linePixelValue = iteratorLineIn.Get();
     testIndex[0] = extractIndex[0];
-    testIndex[1] = iteratorLineIn.GetIndex()[0];
+    testIndex[1] = iteratorLineIn.ComputeIndex()[0];
     if (linePixelValue != if2->GetPixel(testIndex))
     {
       passed = false;

Modules/Core/Common/test/itkImageIteratorTest.cxx

@@ -150,7 +150,7 @@ itkImageIteratorTest(int, char *[])
   }
 
   // Exercise GetIndex()
-  const VectorImageType::IndexType index1 = itr1.GetIndex();
+  const VectorImageType::IndexType index1 = itr1.ComputeIndex();
   if (index1 != startIndex3D)
   {
     std::cerr << "Error in GetIndex()" << std::endl;
@@ -162,13 +162,13 @@ itkImageIteratorTest(int, char *[])
   index2[0]++;
   VectorImageIterator itr5 = itr1;
   itr5.SetIndex(index2);
-  if (itr5.GetIndex() != index2)
+  if (itr5.ComputeIndex() != index2)
   {
     std::cerr << "Error in GetIndex() and/or SetIndex()" << std::endl;
     return EXIT_FAILURE;
   }
 
-  if (itr5.GetIndex() == itr1.GetIndex())
+  if (itr5.ComputeIndex() == itr1.ComputeIndex())
   {
     std::cerr << "Error in GetIndex() and/or SetIndex()" << std::endl;
     return EXIT_FAILURE;

Modules/Core/Common/test/itkImageRegionIteratorTest.cxx

@@ -97,7 +97,7 @@ itkImageRegionIteratorTest(int, char *[])
   std::cout << "Simple iterator loop: ";
   for (; !it.IsAtEnd(); ++it)
   {
-    const itk::Image<itk::Vector<unsigned short, 5>, 3>::IndexType index = it.GetIndex();
+    const itk::Image<itk::Vector<unsigned short, 5>, 3>::IndexType index = it.ComputeIndex();
     std::cout << index << std::endl;
   }
 
@@ -109,7 +109,7 @@ itkImageRegionIteratorTest(int, char *[])
   std::cout << "Simple const iterator loop: ";
   for (; !cit.IsAtEnd(); ++cit)
   {
-    const itk::Image<itk::Vector<unsigned short, 5>, 3>::IndexType index = cit.GetIndex();
+    const itk::Image<itk::Vector<unsigned short, 5>, 3>::IndexType index = cit.ComputeIndex();
     std::cout << index << std::endl;
   }
 
@@ -122,7 +122,7 @@ itkImageRegionIteratorTest(int, char *[])
   {
     --backIt;
 
-    itk::Image<itk::Vector<unsigned short, 5>, 3>::IndexType index = backIt.GetIndex();
+    itk::Image<itk::Vector<unsigned short, 5>, 3>::IndexType index = backIt.ComputeIndex();
     std::cout << "Simple iterator backwards loop: ";
     for (unsigned int i = 0; i < index.GetIndexDimension(); ++i)
     {
@@ -147,7 +147,7 @@ itkImageRegionIteratorTest(int, char *[])
     // Set all pixels with first index == 0 to 0, and set the rest of the image to 255
     while (!createImageIterator.IsAtEnd())
     {
-      if (createImageIterator.GetIndex()[0] == 0)
+      if (createImageIterator.ComputeIndex()[0] == 0)
       {
         createImageIterator.Set(0);
       }

Modules/Core/Common/test/itkImageReverseIteratorTest.cxx

@@ -99,7 +99,7 @@ itkImageReverseIteratorTest(int, char *[])
 
   for (; !it.IsAtEnd(); ++it)
   {
-    ImageType::IndexType index = it.GetIndex();
+    ImageType::IndexType index = it.ComputeIndex();
     std::cout << "Simple iterator loop: ";
     for (unsigned int i = 0; i < index.GetIndexDimension(); ++i)
     {
@@ -115,7 +115,7 @@ itkImageReverseIteratorTest(int, char *[])
   {
     --backIt;
 
-    ImageType::IndexType index = backIt.GetIndex();
+    ImageType::IndexType index = backIt.ComputeIndex();
     std::cout << "Simple iterator backwards loop: ";
     for (unsigned int i = 0; i < index.GetIndexDimension(); ++i)
     {
@@ -183,7 +183,7 @@ itkImageReverseIteratorTest(int, char *[])
   for (; !it.IsAtEnd(); ++it)
   {
     --castBackReverseIt;
-    itk::Image<itk::Vector<unsigned short, 5>, 3>::IndexType index = it.GetIndex();
+    itk::Image<itk::Vector<unsigned short, 5>, 3>::IndexType index = it.ComputeIndex();
     itk::Image<itk::Vector<unsigned short, 5>, 3>::IndexType rindex = castBackReverseIt.GetIndex();
     for (unsigned int i = 0; i < index.GetIndexDimension(); ++i)
     {

Modules/Core/Common/test/itkImageScanlineIteratorTest1.cxx

@@ -162,7 +162,7 @@ itkImageScanlineIteratorTest1(int, char *[])
     {
       while (!createImageIterator.IsAtEndOfLine())
       {
-        if (createImageIterator.GetIndex()[0] == 0)
+        if (createImageIterator.ComputeIndex()[0] == 0)
         {
           createImageIterator.Set(0);
         }

Modules/Core/Common/test/itkImportImageTest.cxx

@@ -96,18 +96,19 @@ itkImportImageTest(int, char *[])
   bool passed = true;
   for (; !iterator2.IsAtEnd(); ++iterator2)
   {
-    std::cout << "Pixel " << iterator2.GetIndex() << " = " << iterator2.Get() << std::endl;
+    std::cout << "Pixel " << iterator2.ComputeIndex() << " = " << iterator2.Get() << std::endl;
     if (iterator2.Get() !=
         itk::Math::RoundHalfIntegerUp<short>(static_cast<float>(
-          (shrink->GetShrinkFactors()[0] * iterator2.GetIndex()[0] + shrink->GetShrinkFactors()[0] / 2) +
+          (shrink->GetShrinkFactors()[0] * iterator2.ComputeIndex()[0] + shrink->GetShrinkFactors()[0] / 2) +
           (region.GetSize()[0] *
-           ((shrink->GetShrinkFactors()[1] / 2) + (shrink->GetShrinkFactors()[0] * iterator2.GetIndex()[1]))))))
+           ((shrink->GetShrinkFactors()[1] / 2) + (shrink->GetShrinkFactors()[0] * iterator2.ComputeIndex()[1]))))))
     {
-      std::cout << " iterator2.GetIndex() Get() " << iterator2.GetIndex() << ' ' << iterator2.Get() << " compare value "
+      std::cout << " iterator2.GetIndex() Get() " << iterator2.ComputeIndex() << ' ' << iterator2.Get()
+                << " compare value "
                 << itk::Math::RoundHalfIntegerUp<short>(static_cast<float>(
-                     (shrink->GetShrinkFactors()[0] * iterator2.GetIndex()[0] + shrink->GetShrinkFactors()[0] / 2) +
+                     (shrink->GetShrinkFactors()[0] * iterator2.ComputeIndex()[0] + shrink->GetShrinkFactors()[0] / 2) +
                      (region.GetSize()[0] * ((shrink->GetShrinkFactors()[1] / 2) +
-                                             (shrink->GetShrinkFactors()[0] * iterator2.GetIndex()[1])))))
+                                             (shrink->GetShrinkFactors()[0] * iterator2.ComputeIndex()[1])))))
                 << '\n';
       passed = false;
     }

Modules/Core/Common/test/itkStreamingImageFilterTest.cxx

@@ -121,17 +121,17 @@ itkStreamingImageFilterTest(int, char *[])
   bool passed = true;
   for (; !iterator2.IsAtEnd(); ++iterator2)
   {
-    short col = (shrink->GetShrinkFactors()[0] * iterator2.GetIndex()[0] + (shrink->GetShrinkFactors()[0] - 1) / 2);
+    short col = (shrink->GetShrinkFactors()[0] * iterator2.ComputeIndex()[0] + (shrink->GetShrinkFactors()[0] - 1) / 2);
     col += colOffset;
 
-    short row = (shrink->GetShrinkFactors()[1] * iterator2.GetIndex()[1] + (shrink->GetShrinkFactors()[1] - 1) / 2);
+    short row = (shrink->GetShrinkFactors()[1] * iterator2.ComputeIndex()[1] + (shrink->GetShrinkFactors()[1] - 1) / 2);
     row += rowOffset;
     const short trueValue = col + region.GetSize()[0] * row;
 
     if (iterator2.Get() != trueValue)
     {
       passed = false;
-      std::cout << "Pixel " << iterator2.GetIndex() << " expected " << trueValue << " but got " << iterator2.Get()
+      std::cout << "Pixel " << iterator2.ComputeIndex() << " expected " << trueValue << " but got " << iterator2.Get()
                 << std::endl;
     }
   }

Modules/Core/Common/test/itkStreamingImageFilterTest2.cxx

@@ -120,18 +120,18 @@ itkStreamingImageFilterTest2(int, char *[])
   for (; !iterator2.IsAtEnd(); ++iterator2)
   {
     auto col = itk::Math::RoundHalfIntegerUp<short>(static_cast<float>(
-      shrink->GetShrinkFactors()[0] * iterator2.GetIndex()[0] + (shrink->GetShrinkFactors()[0]) / 2.0));
+      shrink->GetShrinkFactors()[0] * iterator2.ComputeIndex()[0] + (shrink->GetShrinkFactors()[0]) / 2.0));
     col += colOffset;
 
     auto row = itk::Math::RoundHalfIntegerUp<short>(static_cast<float>(
-      shrink->GetShrinkFactors()[1] * iterator2.GetIndex()[1] + (shrink->GetShrinkFactors()[1]) / 2.0));
+      shrink->GetShrinkFactors()[1] * iterator2.ComputeIndex()[1] + (shrink->GetShrinkFactors()[1]) / 2.0));
     row += rowOffset;
     const short trueValue = col + region.GetSize()[0] * row;
 
     if (iterator2.Get() != trueValue)
     {
       passed = false;
-      std::cout << "Pixel " << iterator2.GetIndex() << " expected " << trueValue << " but got " << iterator2.Get()
+      std::cout << "Pixel " << iterator2.ComputeIndex() << " expected " << trueValue << " but got " << iterator2.Get()
                 << std::endl;
     }
   }

Modules/Core/Common/test/itkSymmetricSecondRankTensorImageReadTest.cxx

@@ -103,7 +103,7 @@ itkSymmetricSecondRankTensorImageReadTest(int argc, char * argv[])
           if (itk::Math::abs(matrixPixel[i][j] - tensorPixel(i, j)) > tolerance)
           {
             std::cerr << "Tensor read does not match expected values " << std::endl;
-            std::cerr << "Index " << tItr.GetIndex() << std::endl;
+            std::cerr << "Index " << tItr.ComputeIndex() << std::endl;
             std::cerr << "Tensor value " << std::endl << tensorPixel << std::endl;
             std::cerr << "Matrix value " << std::endl << matrixPixel << std::endl;
             return EXIT_FAILURE;

Modules/Core/Common/test/itkSymmetricSecondRankTensorImageWriteReadTest.cxx

@@ -88,7 +88,7 @@ itkSymmetricSecondRankTensorImageWriteReadTest(int argc, char * argv[])
         if (itk::Math::abs(tensorPixelInput[i] - tensorPixelOutput[i]) > tolerance)
         {
           std::cerr << "Tensor read does not match expected values " << std::endl;
-          std::cerr << "Index " << inIt.GetIndex() << std::endl;
+          std::cerr << "Index " << inIt.ComputeIndex() << std::endl;
           std::cerr << "Tensor input value " << std::endl << tensorPixelInput << std::endl;
           std::cerr << "Tensor output value " << std::endl << tensorPixelOutput << std::endl;
           return EXIT_FAILURE;

Modules/Core/Mesh/test/itkParametricSpaceToImageSpaceMeshFilterTest.cxx

@@ -35,7 +35,7 @@ struct helper<itk::Index<VDimension>>
   static PositionType
   GetPosition(const TImage *, const TIterator & it)
   {
-    return it.GetIndex();
+    return it.ComputeIndex();
   }
 };
 
@@ -49,7 +49,7 @@ struct helper<itk::Point<TCoord, VDimension>>
   GetPosition(const TImage * image, const TIterator & it)
   {
     typename TImage::PointType p;
-    image->TransformIndexToPhysicalPoint(it.GetIndex(), p);
+    image->TransformIndexToPhysicalPoint(it.ComputeIndex(), p);
 
     PositionType point;
     point.CastFrom(p);

Modules/Core/SpatialObjects/test/itkImageMaskSpatialObjectTest.cxx

@@ -75,7 +75,7 @@ itkImageMaskSpatialObjectTest(int, char *[])
 
   while (!itr.IsAtEnd())
   {
-    const ImageType::IndexType constIndex = itr.GetIndex();
+    const ImageType::IndexType constIndex = itr.ComputeIndex();
     const bool                 reference = insideRegion.IsInside(constIndex);
     ImageType::PointType       point;
     image->TransformIndexToPhysicalPoint(constIndex, point);

Modules/Core/SpatialObjects/test/itkImageMaskSpatialObjectTest2.cxx

@@ -110,7 +110,7 @@ itkImageMaskSpatialObjectTest2(int, char *[])
     itr.GoToBegin();
     while (!itr.IsAtEnd())
     {
-      const ImageType::IndexType constIndex = itr.GetIndex();
+      const ImageType::IndexType constIndex = itr.ComputeIndex();
 
       ImageType::PointType point;
       image->TransformIndexToPhysicalPoint(constIndex, point);
@@ -135,7 +135,7 @@ itkImageMaskSpatialObjectTest2(int, char *[])
     itr.GoToBegin();
     while (!itr.IsAtEnd())
     {
-      const ImageType::IndexType constIndex = itr.GetIndex();
+      const ImageType::IndexType constIndex = itr.ComputeIndex();
       const bool                 reference = insideRegion.IsInside(constIndex);
 
       ImageType::PointType point;