STYLE: Simplify initialization of local region iterators in hxx files

Replaced code like `T x = T(a, b)` and `auto x = T(a, b)` with `T x(a, b)`.

Author: N-Dekker

Modules/Filtering/BinaryMathematicalMorphology/include/itkObjectMorphologyImageFilter.hxx

@@ -98,8 +98,8 @@ ObjectMorphologyImageFilter<TInputImage, TOutputImage, TKernel>::BeforeThreadedG
 
   const RegionType requestedRegion = this->GetOutput()->GetRequestedRegion();
 
-  auto iRegIter = ImageRegionConstIterator(this->GetInput(), requestedRegion);
-  auto oRegIter = ImageRegionIterator(this->GetOutput(), requestedRegion);
+  ImageRegionConstIterator iRegIter(this->GetInput(), requestedRegion);
+  ImageRegionIterator      oRegIter(this->GetOutput(), requestedRegion);
   /* Copy the input image to the output image - then only boundary pixels
    * need to be changed in the output image */
   while (!oRegIter.IsAtEnd())

Modules/Filtering/ImageFeature/include/itkZeroCrossingImageFilter.hxx

@@ -123,9 +123,9 @@ ZeroCrossingImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateData(
     bit.OverrideBoundaryCondition(&nbc);
     bit.GoToBegin();
 
-    static constexpr SizeValueType    neighborhoodSize = Math::UnsignedPower(3, ImageDimension);
-    static constexpr SizeValueType    center = neighborhoodSize / 2;
-    ImageRegionIterator<TOutputImage> it = ImageRegionIterator(output, face);
+    static constexpr SizeValueType neighborhoodSize = Math::UnsignedPower(3, ImageDimension);
+    static constexpr SizeValueType center = neighborhoodSize / 2;
+    ImageRegionIterator            it(output, face);
     while (!bit.IsAtEnd())
     {
       const InputImagePixelType this_one = bit.GetPixel(center);

Modules/Segmentation/Watersheds/include/itkWatershedSegmenter.hxx

@@ -336,8 +336,7 @@ Segmenter<TInputImage>::CollectBoundaryInformation(flat_region_table_t & flatReg
       const ImageRegionType                        region = face->GetRequestedRegion();
 
       // Grab all the labels of the boundary pixels.
-      ImageRegionIterator<typename BoundaryType::face_t> faceIt =
-        ImageRegionIterator<typename BoundaryType::face_t>(face, region);
+      ImageRegionIterator faceIt(face, region);
       ImageRegionIterator labelIt(output, region);
       faceIt.GoToBegin();
       labelIt.GoToBegin();
@@ -443,10 +442,9 @@ Segmenter<TInputImage>::AnalyzeBoundaryFlow(InputImageTypePointer thresholdImage
       const typename BoundaryType::face_t::Pointer face = boundary->GetFace(idx);
       const ImageRegionType                        region = face->GetRequestedRegion();
 
-      ConstNeighborhoodIterator<InputImageType>          searchIt(rad, thresholdImage, region);
-      NeighborhoodIterator<OutputImageType>              labelIt(rad, output, region);
-      ImageRegionIterator<typename BoundaryType::face_t> faceIt =
-        ImageRegionIterator<typename BoundaryType::face_t>(face, region);
+      ConstNeighborhoodIterator<InputImageType> searchIt(rad, thresholdImage, region);
+      NeighborhoodIterator<OutputImageType>     labelIt(rad, output, region);
+      ImageRegionIterator                       faceIt(face, region);
 
       const unsigned int nCenter = searchIt.Size() / 2;
       searchIt.GoToBegin();