ENH: Refactor antsTransformInfo to add some error handling and comput…

…e determinant

Examples/antsTransformInfo.cxx

@@ -19,6 +19,8 @@
 
 #include "antsCommandLineParser.h"
 #include "itkTransformFileReader.h"
+#include "itkAffineTransform.h"
+
 
 #include <sstream>
 
@@ -72,16 +74,52 @@ antsTransformInfo(std::vector<std::string> args, std::ostream * /*out_stream = n
   };
   Cleanup_argv cleanup_argv(argv, argc + 1);
 
+  using ReadScalarType = double;
+
   for (int i = 1; i < argc; i++)
   {
 
     std::cout << "Transform file: " << argv[i] << std::endl;
 
-    itk::TransformFileReader::Pointer reader = itk::TransformFileReader::New();
+    using TransformReaderType = itk::TransformFileReaderTemplate<ReadScalarType>;
+    auto reader = TransformReaderType::New();
+
     reader->SetFileName(argv[i]);
-    reader->Update();
+    try
+    {
+      reader->Update();
+    }
+    catch (const itk::ExceptionObject & excp)
+    {
+      std::cerr << "Error while reading the transform file" << std::endl;
+      std::cerr << excp << std::endl;
+      std::cerr << "[FAILED]" << std::endl;
+      return EXIT_FAILURE;
+    }
+
+    const TransformReaderType::TransformListType * transforms = reader->GetTransformList();
+    std::cout << "Number of transforms = " << transforms->size() << std::endl;
 
-    std::cout << *(reader->GetTransformList()->begin()) << std::endl;
+    unsigned int Dimension = transforms->front()->GetInputSpaceDimension();
+
+
+    for (auto it = transforms->begin(); it != transforms->end(); ++it)
+    {
+      if (Dimension == 3)
+      {
+        using TransformType3D = itk::MatrixOffsetTransformBase<double, 3, 3>;
+        TransformType3D* itktx3d = dynamic_cast<TransformType3D*>((*it).GetPointer());
+        itktx3d->Print(std::cout);
+        std::cout << "Determinant: " << vnl_determinant(itktx3d->GetMatrix().GetVnlMatrix()) << std::endl;
+      }
+      else if (Dimension == 2)
+      {
+        using TransformType2D = itk::MatrixOffsetTransformBase<double, 2, 2>;
+        TransformType2D* itktx2d = dynamic_cast<TransformType2D*>((*it).GetPointer());
+        itktx2d->Print(std::cout);
+        std::cout << "Determinant: " << vnl_determinant(itktx2d->GetMatrix().GetVnlMatrix()) << std::endl;
+      }
+    }
   }
 
   return EXIT_SUCCESS;