FIX: solves a 64-bit type issue in automatic layout configuration

include/lsgrmController.txx

@@ -316,9 +316,9 @@ void Controller<TSegmenter>::GetAutomaticConfiguration()
   itkDebugMacro(<<"Maximum number of nodes in memory is " << maximumNumberOfNodesInMemory);
 
   // Number of nodes in the entire image
-  const unsigned int imageWidth = m_InputImage->GetLargestPossibleRegion().GetSize()[0];
-  const unsigned int imageHeight = m_InputImage->GetLargestPossibleRegion().GetSize()[1];
-  const unsigned long int nbOfNodesInImage = imageWidth*imageHeight;
+  const std::size_t imageWidth = m_InputImage->GetLargestPossibleRegion().GetSize()[0];
+  const std::size_t imageHeight = m_InputImage->GetLargestPossibleRegion().GetSize()[1];
+  const std::size_t nbOfNodesInImage = imageWidth*imageHeight;
 
   // Default layout: 1x1
   m_NbTilesX = 1;