ENH: Make the MaskedInput image an optional named input

Make use of the macros to set named input. This reuses the code in the
macro. By making this input a named input it clarifies the information
printed by the filter when printed.

Author: blowekamp

include/itkCoocurrenceTextureFeaturesImageFilter.h

@@ -128,10 +128,11 @@ class ITK_TEMPLATE_EXPORT CoocurrenceTextureFeaturesImageFilter:public ImageToIm
   itkGetConstMacro(NeighborhoodRadius, NeighborhoodRadiusType);
 
   /** Method to set the mask image */
-  void SetMaskImage( const InputImageType *image );
+  itkSetInputMacro(MaskImage, InputImageType);
 
   /** Method to get the mask image */
-  const InputImageType * GetMaskImage() const;
+  itkGetInputMacro(MaskImage, InputImageType);
+
 
   /** Specify the default number of bins per axis */
   itkStaticConstMacro( DefaultBinsPerAxis, unsigned int, 256 );

include/itkCoocurrenceTextureFeaturesImageFilter.hxx

@@ -38,6 +38,12 @@ CoocurrenceTextureFeaturesImageFilter< TInputImage, TOutputImage >
   this->SetNumberOfRequiredInputs( 1 );
   this->SetNumberOfRequiredOutputs( 1 );
 
+  // Mark the "MaskImage" as an optional named input. First it has to
+  // be added to the list of named inputs then removed from the
+  // required list.
+  Self::AddRequiredInputName("MaskImage");
+  Self::RemoveRequiredInputName("MaskImage");
+
   // Set the offset directions to their defaults: half of all the possible
   // directions 1 pixel away. (The other half is included by symmetry.)
   // We use a neighborhood iterator to calculate the appropriate offsets.
@@ -256,26 +262,6 @@ CoocurrenceTextureFeaturesImageFilter<TInputImage, TOutputImage>
     }
 }
 
-template<typename TInputImage, typename TOutputImage>
-void
-CoocurrenceTextureFeaturesImageFilter<TInputImage, TOutputImage>
-::SetMaskImage(const InputImageType *image )
-{
-  // Process object is not const-correct so the const_cast is required here
-  this->ProcessObject::SetNthInput( 1, const_cast<InputImageType *>( image ) );
-}
-
-template<typename TInputImage, typename TOutputImage>
-const TInputImage *
-CoocurrenceTextureFeaturesImageFilter<TInputImage, TOutputImage>
-::GetMaskImage() const
-{
-  if( this->GetNumberOfInputs() < 2 )
-    {
-    return ITK_NULLPTR;
-    }
-  return static_cast<const InputImageType *>( this->ProcessObject::GetInput( 1 ) );
-}
 
 template<typename TInputImage, typename TOutputImage>
 void