Merge pull request InsightSoftwareConsortium#5077 from blowekamp/comp…

…ose_image_filter_perf Performance improvements to ComposeImageFilter
Kitware · Dec 16, 2024 · be0c8a0 · be0c8a0
2 parents 44e7133 + 25bd86a
commit be0c8a0
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Showing 2 changed files with 35 additions and 34 deletions.
diff --git a/Modules/Filtering/ImageCompose/include/itkComposeImageFilter.h b/Modules/Filtering/ImageCompose/include/itkComposeImageFilter.h
@@ -20,7 +20,7 @@
 
 #include "itkImageToImageFilter.h"
 #include "itkVectorImage.h"
-#include "itkImageRegionConstIterator.h"
+#include "itkImageScanlineIterator.h"
 #include <vector>
 
 namespace itk
@@ -108,27 +108,8 @@ class ITK_TEMPLATE_EXPORT ComposeImageFilter : public ImageToImageFilter<TInputI
 private:
   // we have to specialize the code for complex, because it provides no operator[]
   // method
-  using InputIteratorType = ImageRegionConstIterator<InputImageType>;
+  using InputIteratorType = ImageScanlineConstIterator<InputImageType>;
   using InputIteratorContainerType = std::vector<InputIteratorType>;
-
-  template <typename T>
-  void
-  ComputeOutputPixel(std::complex<T> & pix, InputIteratorContainerType & inputItContainer)
-  {
-    pix = std::complex<T>(inputItContainer[0].Get(), inputItContainer[1].Get());
-    ++(inputItContainer[0]);
-    ++(inputItContainer[1]);
-  }
-  template <typename TPixel>
-  void
-  ComputeOutputPixel(TPixel & pix, InputIteratorContainerType & inputItContainer)
-  {
-    for (unsigned int i = 0; i < this->GetNumberOfInputs(); ++i)
-    {
-      pix[i] = static_cast<typename NumericTraits<OutputPixelType>::ValueType>(inputItContainer[i].Get());
-      ++(inputItContainer[i]);
-    }
-  }
 };
 } // namespace itk
 

diff --git a/Modules/Filtering/ImageCompose/include/itkComposeImageFilter.hxx b/Modules/Filtering/ImageCompose/include/itkComposeImageFilter.hxx
@@ -87,7 +87,7 @@ ComposeImageFilter<TInputImage, TOutputImage>::BeforeThreadedGenerateData()
 
   for (unsigned int i = 0; i < numberOfInputs; ++i)
   {
-    auto * input = itkDynamicCastInDebugMode<InputImageType *>(this->ProcessObject::GetInput(i));
+    auto * input = this->GetInput(i);
     if (!input)
     {
       itkExceptionMacro("Input " << i << " not set!");
@@ -108,33 +108,53 @@ template <typename TInputImage, typename TOutputImage>
 void
 ComposeImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateData(const RegionType & outputRegionForThread)
 {
-  const typename OutputImageType::Pointer outputImage =
-    static_cast<OutputImageType *>(this->ProcessObject::GetOutput(0));
-
+  const typename OutputImageType::Pointer outputImage = this->GetOutput();
 
   TotalProgressReporter progress(this, outputImage->GetRequestedRegion().GetNumberOfPixels());
 
-  ImageRegionIterator<OutputImageType> oit(outputImage, outputRegionForThread);
 
   InputIteratorContainerType inputItContainer;
+  inputItContainer.reserve(this->GetNumberOfIndexedInputs());
 
   for (unsigned int i = 0; i < this->GetNumberOfIndexedInputs(); ++i)
   {
     const InputImageType * inputImage = this->GetInput(i);
 
-    InputIteratorType iit(inputImage, outputRegionForThread);
-    iit.GoToBegin();
-    inputItContainer.push_back(iit);
+    inputItContainer.emplace_back(inputImage, outputRegionForThread);
   }
 
   OutputPixelType pix;
   NumericTraits<OutputPixelType>::SetLength(pix, static_cast<unsigned int>(this->GetNumberOfIndexedInputs()));
-  while (!oit.IsAtEnd())
+  for (ImageScanlineIterator oit(outputImage, outputRegionForThread); !oit.IsAtEnd(); oit.NextLine())
   {
-    ComputeOutputPixel(pix, inputItContainer);
-    oit.Set(pix);
-    ++oit;
-    progress.CompletedPixel();
+    while (!oit.IsAtEndOfLine())
+    {
+      if constexpr (std::is_same<OutputPixelType,
+                                 std::complex<typename NumericTraits<OutputPixelType>::ValueType>>::value)
+      {
+        oit.Set({ inputItContainer[0].Get(), inputItContainer[1].Get() });
+        ++(inputItContainer[0]);
+        ++(inputItContainer[1]);
+      }
+      else
+      {
+        unsigned int i = 0;
+        for (auto & it : inputItContainer)
+        {
+          pix[i] = static_cast<typename NumericTraits<OutputPixelType>::ValueType>(it.Get());
+          ++i;
+          ++it;
+        }
+
+        oit.Set(pix);
+      }
+      ++oit;
+    }
+    for (auto & it : inputItContainer)
+    {
+      it.NextLine();
+    }
+    progress.Completed(outputRegionForThread.GetSize()[0]);
   }
 }
 } // end namespace itk