Add ComputeIndex() member function to ImageConstIterator

Modules/Core/Common/include/itkImageConstIterator.h

@@ -295,16 +295,24 @@ class ITK_TEMPLATE_EXPORT ImageConstIterator
     return (m_Buffer + m_Offset) > (it.m_Buffer + it.m_Offset);
   }
 
-  /** Get the index. This provides a read only reference to the index.
-   * This causes the index to be calculated from pointer arithmetic and is
-   * therefore an expensive operation.
+  /** Computes the index. Internally calls ImageBase::ComputeIndex, which may be a relatively expensive operation.
    * \sa SetIndex */
   [[nodiscard]] IndexType
-  GetIndex() const
+  ComputeIndex() const
   {
     return m_Image->ComputeIndex(m_Offset);
   }
 
+  /** 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 */
+  [[nodiscard]] IndexType
+  GetIndex() const
+  {
+    return this->ComputeIndex();
+  }
+
   /** Set the index. No bounds checking is performed.
    * \sa GetIndex */
   virtual void

Modules/Core/Common/include/itkImageReverseConstIterator.h

@@ -207,7 +207,7 @@ class ITK_TEMPLATE_EXPORT ImageReverseConstIterator
   {
 
 
-    const IndexType ind = it.GetIndex();
+    const IndexType ind = it.ComputeIndex();
 
     m_Offset = m_Image->ComputeOffset(ind);
 

Modules/Core/Common/include/itkImageScanlineConstIterator.h

@@ -117,7 +117,7 @@ class ITK_TEMPLATE_EXPORT ImageScanlineConstIterator : public ImageConstIterator
   {
     this->ImageConstIterator<TImage>::operator=(it);
 
-    IndexType ind = this->GetIndex();
+    IndexType ind = this->ComputeIndex();
     m_SpanEndOffset = this->m_Offset + static_cast<OffsetValueType>(this->m_Region.GetSize()[0]) -
                       (ind[0] - this->m_Region.GetIndex()[0]);
     m_SpanBeginOffset = m_SpanEndOffset - static_cast<OffsetValueType>(this->m_Region.GetSize()[0]);

Modules/Filtering/DisplacementField/include/itkInvertDisplacementFieldImageFilter.hxx

@@ -194,7 +194,7 @@ InvertDisplacementFieldImageFilter<TInputImage, TOutputImage>::DynamicThreadedGe
       }
       update = ItI.Get() + update * this->m_Epsilon;
       ItI.Set(update);
-      typename DisplacementFieldType::IndexType index = ItI.GetIndex();
+      typename DisplacementFieldType::IndexType index = ItI.ComputeIndex();
       if (this->m_EnforceBoundaryCondition)
       {
         for (unsigned int d = 0; d < ImageDimension; ++d)

Modules/Filtering/DisplacementField/include/itkIterativeInverseDisplacementFieldImageFilter.hxx

@@ -98,7 +98,7 @@ IterativeInverseDisplacementFieldImageFilter<TInputImage, TOutputImage>::Generat
     while (!OutputIt.IsAtEnd())
     {
       // get the output image index
-      const OutputImageIndexType index = OutputIt.GetIndex();
+      const OutputImageIndexType index = OutputIt.ComputeIndex();
       OutputImagePointType       originalPoint;
       outputPtr->TransformIndexToPhysicalPoint(index, originalPoint);
 

Modules/Filtering/DisplacementField/include/itkTransformToDisplacementFieldFilter.hxx

@@ -192,7 +192,7 @@ TransformToDisplacementFieldFilter<TOutputImage, TParametersValueType>::Nonlinea
     while (!outIt.IsAtEndOfLine())
     {
       // Determine the index of the current output pixel
-      output->TransformIndexToPhysicalPoint(outIt.GetIndex(), outputPoint);
+      output->TransformIndexToPhysicalPoint(outIt.ComputeIndex(), outputPoint);
 
       // Compute corresponding input pixel position
       transformedPoint = transform->TransformPoint(outputPoint);
@@ -235,7 +235,7 @@ TransformToDisplacementFieldFilter<TOutputImage, TParametersValueType>::LinearTh
     // The region may be split along the fast scan-line direction, so
     // the computation is done for the beginning and end of the largest
     // possible region to improve consistent numerics.
-    IndexType index = outIt.GetIndex();
+    IndexType index = outIt.ComputeIndex();
     index[0] = largestPossibleRegion.GetIndex(0);
 
     outputPtr->TransformIndexToPhysicalPoint(index, outputPoint);
@@ -247,7 +247,7 @@ TransformToDisplacementFieldFilter<TOutputImage, TParametersValueType>::LinearTh
     inputPoint = transformPtr->TransformPoint(outputPoint);
     const typename PointType::VectorType endDisplacement = inputPoint - outputPoint;
 
-    IndexValueType scanlineIndex = outIt.GetIndex()[0];
+    IndexValueType scanlineIndex = outIt.ComputeIndex()[0];
 
     while (!outIt.IsAtEndOfLine())
     {

Modules/Filtering/ImageFeature/include/itkCannyEdgeDetectionImageFilter.hxx

@@ -294,9 +294,9 @@ CannyEdgeDetectionImageFilter<TInputImage, TOutputImage>::HysteresisThresholding
     if (value > m_UpperThreshold)
     {
       node = m_NodeStore->Borrow();
-      node->m_Value = oit.GetIndex();
+      node->m_Value = oit.ComputeIndex();
       m_NodeList->PushFront(node);
-      FollowEdge(oit.GetIndex(), multiplyImageFilterOutput);
+      FollowEdge(oit.ComputeIndex(), multiplyImageFilterOutput);
     }
 
     ++oit;

Modules/Filtering/ImageFeature/include/itkHoughTransform2DLinesImageFilter.hxx

@@ -282,8 +282,8 @@ HoughTransform2DLinesImageFilter<TInputPixelType, TOutputPixelType>::GetLines()
           // Create the line.
           LineType::LinePointListType list; // Insert two points per line.
 
-          const double radius = it_input.GetIndex()[0];
-          const double teta = ((it_input.GetIndex()[1]) * 2 * Math::pi / this->GetAngleResolution()) - Math::pi;
+          const double radius = it_input.ComputeIndex()[0];
+          const double teta = ((it_input.ComputeIndex()[1]) * 2 * Math::pi / this->GetAngleResolution()) - Math::pi;
           const double Vx = radius * std::cos(teta);
           const double Vy = radius * std::sin(teta);
           const double norm = std::sqrt(Vx * Vx + Vy * Vy);
@@ -326,8 +326,8 @@ HoughTransform2DLinesImageFilter<TInputPixelType, TOutputPixelType>::GetLines()
           {
             for (double length = 0; length < m_DiscRadius; length += 1)
             {
-              index[0] = static_cast<IndexValueType>(it_input.GetIndex()[0] + length * std::cos(angle));
-              index[1] = static_cast<IndexValueType>(it_input.GetIndex()[1] + length * std::sin(angle));
+              index[0] = static_cast<IndexValueType>(it_input.ComputeIndex()[0] + length * std::cos(angle));
+              index[1] = static_cast<IndexValueType>(it_input.ComputeIndex()[1] + length * std::sin(angle));
               if (postProcessImage->GetBufferedRegion().IsInside(index))
               {
                 postProcessImage->SetPixel(index, 0);

Modules/Filtering/ImageGradient/include/itkDifferenceOfGaussiansGradientImageFilter.hxx

@@ -76,7 +76,7 @@ DifferenceOfGaussiansGradientImageFilter<TInputImage, TDataType>::GenerateData()
   for (; !outIt.IsAtEnd(); ++outIt)
   {
     // determine the index of the output pixel
-    outputIndex = outIt.GetIndex();
+    outputIndex = outIt.ComputeIndex();
 
     // is the current index an acceptable distance from the edges
     // of the image?

Modules/Filtering/ImageGrid/include/itkBinShrinkImageFilter.hxx

@@ -155,7 +155,7 @@ BinShrinkImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateData(
   for (ImageScanlineIterator outputIterator(outputPtr, outputRegionForThread); !outputIterator.IsAtEnd();
        outputIterator.NextLine())
   {
-    const OutputIndexType outputIndex = outputIterator.GetIndex();
+    const OutputIndexType outputIndex = outputIterator.ComputeIndex();
 
     auto                 offset = offsets.begin();
     const InputIndexType startInputIndex = outputIndex * factorSize;

Modules/Filtering/ImageGrid/include/itkExpandImageFilter.hxx

@@ -113,7 +113,7 @@ ExpandImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateData(
   // Walk the output region, and interpolate the input image
   for (ImageScanlineIterator outIt(outputPtr, outputRegionForThread); !outIt.IsAtEnd(); outIt.NextLine())
   {
-    const typename OutputImageType::IndexType outputIndex = outIt.GetIndex();
+    const typename OutputImageType::IndexType outputIndex = outIt.ComputeIndex();
 
 
     // Determine the input pixel location associated with this output

Modules/Filtering/ImageGrid/include/itkFlipImageFilter.hxx

@@ -190,7 +190,7 @@ FlipImageFilter<TImage>::DynamicThreadedGenerateData(const OutputImageRegionType
   for (ImageScanlineIterator outputIt(outputPtr, outputRegionForThread); !outputIt.IsAtEnd(); outputIt.NextLine())
   {
     // Determine the index of the output line
-    const typename TImage::IndexType outputIndex = outputIt.GetIndex();
+    const typename TImage::IndexType outputIndex = outputIt.ComputeIndex();
 
     // Determine the input pixel location associated with the start of
     // the line

Modules/Filtering/ImageGrid/include/itkMirrorPadImageFilter.hxx

@@ -756,7 +756,7 @@ MirrorPadImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateData(
         InputIterator       inIt(inputPtr, inputRegion);
         for (OutputIterator outIt(outputPtr, outputRegion); !outIt.IsAtEnd(); ++outIt, i++, ++inIt)
         {
-          OutputImageIndexType currentOutputIndex = outIt.GetIndex();
+          OutputImageIndexType currentOutputIndex = outIt.ComputeIndex();
 
           this->ConvertOutputIndexToInputIndex(
             currentOutputIndex, currentInputIndex, outputRegion, inputRegion, oddRegionArray, decayFactor);

Modules/Filtering/ImageGrid/include/itkResampleImageFilter.hxx

@@ -466,14 +466,14 @@ ResampleImageFilter<TInputImage, TOutputImage, TInterpolatorPrecisionType, TTran
     // Determine the continuous index of the first and end pixel of output
     // scan line when mapped to the input coordinate frame.
 
-    IndexType index = outIt.GetIndex();
+    IndexType index = outIt.ComputeIndex();
     index[0] = firstIndexValueOfLargestPossibleRegion;
 
     const ContinuousInputIndexType startIndex = transformIndex(index);
     index[0] += firstSizeValueOfLargestPossibleRegion;
     const auto vectorFromStartIndex = transformIndex(index) - startIndex;
 
-    IndexValueType scanlineIndex = outIt.GetIndex()[0];
+    IndexValueType scanlineIndex = outIt.ComputeIndex()[0];
 
 
     while (!outIt.IsAtEndOfLine())

Modules/Filtering/ImageLabel/include/itkBinaryContourImageFilter.hxx

@@ -130,7 +130,7 @@ BinaryContourImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateData
 
   for (inLineIt.GoToBegin(); !inLineIt.IsAtEnd(); inLineIt.NextLine(), outLineIt.NextLine())
   {
-    SizeValueType    lineId = this->IndexToLinearIndex(inLineIt.GetIndex());
+    SizeValueType    lineId = this->IndexToLinearIndex(inLineIt.ComputeIndex());
     LineEncodingType fgLine;
     LineEncodingType bgLine;
 
@@ -142,7 +142,7 @@ BinaryContourImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateData
       {
         // We've hit the start of a run
         SizeValueType   length = 0;
-        const IndexType thisIndex = inLineIt.GetIndex();
+        const IndexType thisIndex = inLineIt.ComputeIndex();
 
         outLineIt.Set(m_BackgroundValue);
 
@@ -164,7 +164,7 @@ BinaryContourImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateData
       {
         // We've hit the start of a run
         SizeValueType   length = 0;
-        const IndexType thisIndex = inLineIt.GetIndex();
+        const IndexType thisIndex = inLineIt.ComputeIndex();
 
         outLineIt.Set(PVal);
         ++length;
@@ -198,7 +198,7 @@ BinaryContourImageFilter<TInputImage, TOutputImage>::ThreadedIntegrateData(const
 
   for (ImageScanlineIterator outLineIt(output, outputRegionForThread); !outLineIt.IsAtEnd(); outLineIt.NextLine())
   {
-    const SizeValueType thisIdx = this->IndexToLinearIndex(outLineIt.GetIndex());
+    const SizeValueType thisIdx = this->IndexToLinearIndex(outLineIt.ComputeIndex());
     if (!m_ForegroundLineMap[thisIdx].empty())
     {
       for (auto I = this->m_LineOffsets.begin(); I != this->m_LineOffsets.end(); ++I)

Modules/Filtering/ImageLabel/include/itkLabelContourImageFilter.hxx

@@ -120,14 +120,14 @@ LabelContourImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateData(
 
   for (inLineIt.GoToBegin(); !inLineIt.IsAtEnd(); inLineIt.NextLine(), outLineIt.NextLine())
   {
-    const SizeValueType lineId = this->IndexToLinearIndex(inLineIt.GetIndex());
+    const SizeValueType lineId = this->IndexToLinearIndex(inLineIt.ComputeIndex());
     LineEncodingType    thisLine;
     while (!inLineIt.IsAtEndOfLine())
     {
       const InputPixelType PVal = inLineIt.Get();
 
       SizeValueType        length = 0;
-      const InputIndexType thisIndex = inLineIt.GetIndex();
+      const InputIndexType thisIndex = inLineIt.ComputeIndex();
       outLineIt.Set(m_BackgroundValue);
       ++length;
       ++inLineIt;
@@ -162,7 +162,7 @@ LabelContourImageFilter<TInputImage, TOutputImage>::ThreadedIntegrateData(
 
   for (ImageScanlineIterator outLineIt(output, outputRegionForThread); !outLineIt.IsAtEnd(); outLineIt.NextLine())
   {
-    const SizeValueType thisIdx = this->IndexToLinearIndex(outLineIt.GetIndex());
+    const SizeValueType thisIdx = this->IndexToLinearIndex(outLineIt.ComputeIndex());
     if (!m_LineMap[thisIdx].empty())
     {
       for (auto I = this->m_LineOffsets.begin(); I != this->m_LineOffsets.end(); ++I)

Modules/Filtering/ImageSources/include/itkGaussianImageSource.hxx

@@ -102,7 +102,7 @@ GaussianImageSource<TOutputImage>::GenerateData()
   // Walk the output image, evaluating the spatial function at each pixel
   for (OutputIterator outIt(outputPtr, outputPtr->GetRequestedRegion()); !outIt.IsAtEnd(); ++outIt)
   {
-    const typename TOutputImage::IndexType index = outIt.GetIndex();
+    const typename TOutputImage::IndexType index = outIt.ComputeIndex();
     // The position at which the function is evaluated
     typename FunctionType::InputType evalPoint;
     outputPtr->TransformIndexToPhysicalPoint(index, evalPoint);

Modules/Filtering/ImageStatistics/include/itkAccumulateImageFilter.hxx

@@ -168,7 +168,7 @@ AccumulateImageFilter<TInputImage, TOutputImage>::GenerateData()
   }
   while (!outputIter.IsAtEnd())
   {
-    typename TOutputImage::IndexType OutputIndex = outputIter.GetIndex();
+    typename TOutputImage::IndexType OutputIndex = outputIter.ComputeIndex();
     for (unsigned int i = 0; i < InputImageDimension; ++i)
     {
       if (i != m_AccumulateDimension)

Modules/Filtering/LabelMap/include/itkBinaryImageToLabelMapFilter.hxx

@@ -167,7 +167,7 @@ BinaryImageToLabelMapFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateD
       {
         // We've hit the start of a run
         SizeValueType   length = 0;
-        const IndexType thisIndex = inLineIt.GetIndex();
+        const IndexType thisIndex = inLineIt.ComputeIndex();
         ++length;
         ++inLineIt;
         while (!inLineIt.IsAtEndOfLine() && inLineIt.Get() == this->m_InputForegroundValue)

Modules/Filtering/MathematicalMorphology/include/itkValuedRegionalExtremaImageFilter.hxx

@@ -131,7 +131,7 @@ ValuedRegionalExtremaImageFilter<TInputImage, TOutputImage, TFunction1, TFunctio
       if (compareOut(V, m_MarkerValue))
       {
         // reposition the input iterator
-        inNIt += outIt.GetIndex() - inNIt.GetIndex();
+        inNIt += outIt.ComputeIndex() - inNIt.GetIndex();
 
         auto Cent = static_cast<InputImagePixelType>(V);
 
@@ -156,7 +156,7 @@ ValuedRegionalExtremaImageFilter<TInputImage, TOutputImage, TFunction1, TFunctio
             // indexes of all neighbors with value V on the stack. The
             // process terminates when the stack is empty.
 
-            outNIt += outIt.GetIndex() - outNIt.GetIndex();
+            outNIt += outIt.ComputeIndex() - outNIt.GetIndex();
 
             OutputImagePixelType NVal;
             OutIndexType         idx;

Modules/Filtering/Path/include/itkContourExtractor2DImageFilter.hxx

@@ -352,10 +352,10 @@ ContourExtractor2DImageFilter<TInputImage>::GenerateDataForLabels()
     for (inputIt.GoToBegin(); !inputIt.IsAtEnd(); ++inputIt)
     {
       BoundingBoxType & bbox = labelBoundingBoxes[inputIt.Get()];
-      bbox.min[0] = std::min(bbox.min[0], inputIt.GetIndex()[0]);
-      bbox.min[1] = std::min(bbox.min[1], inputIt.GetIndex()[1]);
-      bbox.max[0] = std::max(bbox.max[0], inputIt.GetIndex()[0]);
-      bbox.max[1] = std::max(bbox.max[1], inputIt.GetIndex()[1]);
+      bbox.min[0] = std::min(bbox.min[0], inputIt.ComputeIndex()[0]);
+      bbox.min[1] = std::min(bbox.min[1], inputIt.ComputeIndex()[1]);
+      bbox.max[0] = std::max(bbox.max[0], inputIt.ComputeIndex()[0]);
+      bbox.max[1] = std::max(bbox.max[1], inputIt.ComputeIndex()[1]);
     }
     // Build the extended regions from the bounding boxes
     for (const InputPixelType label : allLabels)

Modules/Filtering/Smoothing/include/itkBinomialBlurImageFilter.hxx

@@ -150,7 +150,7 @@ BinomialBlurImageFilter<TInputImage, TOutputImage>::GenerateData()
       while (!tempItDir.IsAtEnd())
       {
         // determine the index of the output pixel
-        index = tempItDir.GetIndex();
+        index = tempItDir.ComputeIndex();
 
         if (index[dim] < (startIndex[dim] + static_cast<typename TTempImage::OffsetValueType>(size[dim]) - 1))
         {

Modules/Filtering/SpatialFunction/include/itkSpatialFunctionImageEvaluatorFilter.hxx

@@ -56,7 +56,7 @@ SpatialFunctionImageEvaluatorFilter<TSpatialFunction, TInputImage, TOutputImage>
   // Walk the output image, evaluating the spatial function at each pixel
   for (; !outIt.IsAtEnd(); ++outIt)
   {
-    const typename TOutputImage::IndexType index = outIt.GetIndex();
+    const typename TOutputImage::IndexType index = outIt.ComputeIndex();
     outputPtr->TransformIndexToPhysicalPoint(index, evalPoint);
     value = m_PixelFunction->Evaluate(evalPoint);
 

Modules/Numerics/FEM/include/itkFEMRobustSolver.hxx

@@ -1034,7 +1034,7 @@ RobustSolver<VDimension>::InitializeInterpolationGrid()
     {
       // Note: Iterator is guaranteed to be within image, since the
       // elements with BB outside are skipped before.
-      this->m_InterpolationGrid->TransformIndexToPhysicalPoint(iter.GetIndex(), pt);
+      this->m_InterpolationGrid->TransformIndexToPhysicalPoint(iter.ComputeIndex(), pt);
       for (FEMIndexType d = 0; d < NumberOfDimensions; ++d)
       {
         global_point[d] = pt[d];

Modules/Numerics/FEM/include/itkFEMScatteredDataPointSetToImageFilter.hxx

@@ -711,7 +711,7 @@ FEMScatteredDataPointSetToImageFilter<TInputPointSet,
   // step over all points within the region
   for (iter.GoToBegin(); !iter.IsAtEnd(); ++iter)
   {
-    output->TransformIndexToPhysicalPoint(iter.GetIndex(), point);
+    output->TransformIndexToPhysicalPoint(iter.ComputeIndex(), point);
     for (unsigned int d = 0; d < ImageDimension; ++d)
     {
       globalPoint[d] = point[d];

Modules/Numerics/FEM/include/itkFEMSolver.hxx

@@ -840,7 +840,7 @@ Solver<VDimension>::FillInterpolationGrid()
     {
       // Note: Iterator is guaranteed to be within image, since the
       //       elements with BB outside are skipped before.
-      m_InterpolationGrid->TransformIndexToPhysicalPoint(iter.GetIndex(), pt);
+      m_InterpolationGrid->TransformIndexToPhysicalPoint(iter.ComputeIndex(), pt);
       for (unsigned int d = 0; d < NumberOfDimensions; ++d)
       {
         global_point[d] = pt[d];

Modules/Segmentation/ConnectedComponents/include/itkConnectedComponentImageFilter.hxx

@@ -180,7 +180,7 @@ ConnectedComponentImageFilter<TInputImage, TOutputImage, TMaskImage>::DynamicThr
       if (PVal != NumericTraits<InputPixelType>::ZeroValue(PVal))
       {
         // We've hit the start of a run
-        const IndexType thisIndex = inLineIt.GetIndex();
+        const IndexType thisIndex = inLineIt.ComputeIndex();
         // std::cout << thisIndex << std::endl;
         SizeValueType length = 1;
         ++inLineIt;

Modules/Segmentation/ConnectedComponents/include/itkHardConnectedComponentImageFilter.hxx

@@ -69,7 +69,7 @@ HardConnectedComponentImageFilter<TInputImage, TOutputImage>::GenerateData()
     {
       for (unsigned int i = 0; i < ImageDimension; ++i)
       {
-        IndexType currentIndex = ot.GetIndex();
+        IndexType currentIndex = ot.ComputeIndex();
         currentIndex[i] = currentIndex[i] - 1;
         LabelType label = 0;
         if (currentIndex[i] >= 0)

Modules/Segmentation/LevelSets/include/itkLevelSetNeighborhoodExtractor.hxx

@@ -139,7 +139,7 @@ LevelSetNeighborhoodExtractor<TLevelSet>::GenerateDataFull()
       this->UpdateProgress(static_cast<float>(i) / static_cast<float>(totalPixels));
     }
 
-    inputIndex = inIt.GetIndex();
+    inputIndex = inIt.ComputeIndex();
     this->CalculateDistance(inputIndex);
   }
 }