PERF: Use FastEvaluate in MattesMutualInformationImageToImageMetric + v4

Removed the two dynamically allocated "cubic BSpline kernel" data members from both `MattesMutualInformationImageToImageMetric` and `MattesMutualInformationImageToImageMetricv4`. Replaced the virtual `Evaluate` function calls by faster static member function calls, to the newly added `FastEvaluate` member functions of the corresponding `KernelFunction` classes. Follow-up to pull request #2716 commit c23944b "PERF: Remove BSplineInterpolationWeightFunction Kernel, use FastEvaluate"
InsightSoftwareConsortium · Sep 14, 2021 · 9961ccd · 9961ccd
1 parent 760ae12
commit 9961ccd
Show file tree

Hide file tree

Showing 5 changed files with 6 additions and 27 deletions.
diff --git a/Modules/Registration/Common/include/itkMattesMutualInformationImageToImageMetric.h b/Modules/Registration/Common/include/itkMattesMutualInformationImageToImageMetric.h
@@ -323,10 +323,6 @@ class ITK_TEMPLATE_EXPORT MattesMutualInformationImageToImageMetric
   PDFValueType  m_FixedImageBinSize{ 0.0 };
   PDFValueType  m_MovingImageBinSize{ 0.0 };
 
-  /** Cubic BSpline kernel for computing Parzen histograms. */
-  typename CubicBSplineFunctionType::Pointer           m_CubicBSplineKernel;
-  typename CubicBSplineDerivativeFunctionType::Pointer m_CubicBSplineDerivativeKernel;
-
   /** Helper array for storing the values of the JointPDF ratios. */
   using PRatioType = PDFValueType;
   using PRatioArrayType = Array2D<PRatioType>;

diff --git a/Modules/Registration/Common/include/itkMattesMutualInformationImageToImageMetric.hxx b/Modules/Registration/Common/include/itkMattesMutualInformationImageToImageMetric.hxx
@@ -34,9 +34,7 @@ namespace itk
  */
 template <typename TFixedImage, typename TMovingImage>
 MattesMutualInformationImageToImageMetric<TFixedImage, TMovingImage>::MattesMutualInformationImageToImageMetric()
-  : m_CubicBSplineKernel(nullptr)
-  , m_CubicBSplineDerivativeKernel(nullptr)
-  , m_PRatioArray(0, 0)
+  : m_PRatioArray(0, 0)
   ,
   // Initialize memory
   m_MovingImageMarginalPDF(0)
@@ -338,11 +336,6 @@ MattesMutualInformationImageToImageMetric<TFixedImage, TMovingImage>::Initialize
       this->m_MMIMetricPerThreadVariables[workUnitID].MetricDerivative.Fill(NumericTraits<MeasureType>::ZeroValue());
     }
   }
-  /**
-   * Setup the kernels used for the Parzen windows.
-   */
-  this->m_CubicBSplineKernel = CubicBSplineFunctionType::New();
-  this->m_CubicBSplineDerivativeKernel = CubicBSplineDerivativeFunctionType::New();
 
   /**
    * Pre-compute the fixed image parzen window index for
@@ -460,7 +453,7 @@ MattesMutualInformationImageToImageMetric<TFixedImage, TMovingImage>::GetValueTh
 
   while (pdfMovingIndex <= pdfMovingIndexMax)
   {
-    *(pdfPtr++) += static_cast<PDFValueType>(this->m_CubicBSplineKernel->Evaluate(movingImageParzenWindowArg));
+    *(pdfPtr++) += CubicBSplineFunctionType::FastEvaluate(movingImageParzenWindowArg);
     movingImageParzenWindowArg += 1;
     ++pdfMovingIndex;
   }
@@ -705,13 +698,13 @@ MattesMutualInformationImageToImageMetric<TFixedImage, TMovingImage>::GetValueAn
 
   while (pdfMovingIndex <= pdfMovingIndexMax)
   {
-    *(pdfPtr++) += static_cast<PDFValueType>(this->m_CubicBSplineKernel->Evaluate(movingImageParzenWindowArg));
+    *(pdfPtr++) += CubicBSplineFunctionType::FastEvaluate(movingImageParzenWindowArg);
 
     if (this->m_UseExplicitPDFDerivatives || this->m_ImplicitDerivativesSecondPass)
     {
       // Compute the cubicBSplineDerivative for later repeated use.
       const PDFValueType cubicBSplineDerivativeValue =
-        this->m_CubicBSplineDerivativeKernel->Evaluate(movingImageParzenWindowArg);
+        CubicBSplineDerivativeFunctionType::FastEvaluate(movingImageParzenWindowArg);
 
       // Compute PDF derivative contribution.
       this->ComputePDFDerivatives(

diff --git a/Modules/Registration/Metricsv4/include/itkMattesMutualInformationImageToImageMetricv4.h b/Modules/Registration/Metricsv4/include/itkMattesMutualInformationImageToImageMetricv4.h
@@ -255,10 +255,6 @@ class ITK_TEMPLATE_EXPORT MattesMutualInformationImageToImageMetricv4
   PDFValueType  m_FixedImageBinSize;
   PDFValueType  m_MovingImageBinSize;
 
-  /** Cubic BSpline kernel for computing Parzen histograms. */
-  typename CubicBSplineFunctionType::Pointer           m_CubicBSplineKernel;
-  typename CubicBSplineDerivativeFunctionType::Pointer m_CubicBSplineDerivativeKernel;
-
   /** Helper array for storing the values of the JointPDF ratios. */
   using PRatioType = PDFValueType;
   using PRatioArrayType = std::vector<PRatioType>;

diff --git a/Modules/Registration/Metricsv4/include/itkMattesMutualInformationImageToImageMetricv4.hxx b/Modules/Registration/Metricsv4/include/itkMattesMutualInformationImageToImageMetricv4.hxx
@@ -43,8 +43,6 @@ MattesMutualInformationImageToImageMetricv4<TFixedImage,
   , m_MovingImageTrueMax(0.0)
   , m_FixedImageBinSize(0.0)
   , m_MovingImageBinSize(0.0)
-  , m_CubicBSplineKernel(nullptr)
-  , m_CubicBSplineDerivativeKernel(nullptr)
   , m_PRatioArray(0)
   ,
   // Initialize memory
@@ -60,8 +58,6 @@ MattesMutualInformationImageToImageMetricv4<TFixedImage,
   // ImageToImageMetricv4 to use.
   this->m_DenseGetValueAndDerivativeThreader = MattesMutualInformationDenseGetValueAndDerivativeThreaderType::New();
   this->m_SparseGetValueAndDerivativeThreader = MattesMutualInformationSparseGetValueAndDerivativeThreaderType::New();
-  this->m_CubicBSplineKernel = CubicBSplineFunctionType::New();
-  this->m_CubicBSplineDerivativeKernel = CubicBSplineDerivativeFunctionType::New();
 }
 
 /**

diff --git a/...4/include/itkMattesMutualInformationImageToImageMetricv4GetValueAndDerivativeThreader.hxx b/...4/include/itkMattesMutualInformationImageToImageMetricv4GetValueAndDerivativeThreader.hxx
@@ -345,16 +345,14 @@ MattesMutualInformationImageToImageMetricv4GetValueAndDerivativeThreader<
                                        MovingTransformType::TransformCategoryEnum::DisplacementField;
   while (pdfMovingIndex <= pdfMovingIndexMax)
   {
-    const auto val =
-      static_cast<PDFValueType>(this->m_MattesAssociate->m_CubicBSplineKernel->Evaluate(movingImageParzenWindowArg));
+    const auto val = CubicBSplineFunctionType::FastEvaluate(movingImageParzenWindowArg);
     *(pdfPtr++) += val;
 
     if (doComputeDerivative)
     {
       // Compute the cubicBSplineDerivative for later repeated use.
       const PDFValueType cubicBSplineDerivativeValue =
-        this->m_MattesAssociate->m_CubicBSplineDerivativeKernel->Evaluate(movingImageParzenWindowArg);
-
+        CubicBSplineDerivativeFunctionType::FastEvaluate(movingImageParzenWindowArg);
 
       if (transformIsDisplacement)
       {