ENH: Add test to improve vtkDICOMImageReader coverage.

This patch set adds a new test to exercise the vtkDICOMImageReader's
ability to parse a folder containing DICOM files.

The DICOM files were generated using David Gobbi's niftitodicom tool from
the vtk-dicom project, and using the filtered_func_data.nii.gz NIfTI file
already present in VTK's testing data. Only 10 slices around the central
axial region of the volume are included to limit the testing data size.

IO/Image/Testing/Cxx/CMakeLists.txt

@@ -1,3 +1,8 @@
+# Tell ExternalData to fetch test input at build time.
+  ExternalData_Expand_Arguments(VTKData _
+    "DATA{${VTK_TEST_INPUT_DIR}/dicom/collection/,REGEX:.*}"
+    )
+
 vtk_add_test_cxx(${vtk-module}CxxTests data_tests
   # TestImageReader2Factory.cxx   # fixme (deps not satisfied)
   TestNrrdReader.cxx
@@ -13,11 +18,15 @@ vtk_add_test_cxx(${vtk-module}CxxTests tests
   TestImportExport.cxx
   )
 
-# Each of these most be added in a separate vtk_add_test_cxx
+# Each of these must be added in a separate vtk_add_test_cxx
 vtk_add_test_cxx(${vtk-module}CxxTests tests
   TestDICOMImageReader.cxx,NO_OUTPUT
     "DATA{${VTK_TEST_INPUT_DIR}/dicom/prostate.IMG}")
 
+vtk_add_test_cxx(${vtk-module}CxxTests tests
+  TestDICOMImageReaderFileCollection.cxx,NO_OUTPUT
+    "collection")
+
 vtk_add_test_cxx(${vtk-module}CxxTests tests
   TestTIFFReaderMultipleMulti,TestTIFFReaderMultiple.cxx,NO_VALID,NO_OUTPUT
     "DATA{${VTK_TEST_INPUT_DIR}/libtiff/multipage_tiff_example.tif}")

IO/Image/Testing/Cxx/TestDICOMImageReaderFileCollection.cxx

@@ -0,0 +1,128 @@
+/*=========================================================================
+
+  Program:   Visualization Toolkit
+  Module:    TestDICOMImageReaderFileCollection.cxx
+
+  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
+  All rights reserved.
+  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+     PURPOSE.  See the above copyright notice for more information.
+
+=========================================================================*/
+// .NAME Test of vtkDICOMImageReader
+// .SECTION Description
+//
+
+
+#include "vtkSmartPointer.h"
+
+#include "vtkDICOMImageReader.h"
+
+#include "vtkImageData.h"
+#include "vtkImageViewer2.h"
+#include "vtkRenderer.h"
+#include "vtkRenderWindowInteractor.h"
+#include "vtkTestUtilities.h"
+
+
+int TestDICOMImageReaderFileCollection(int argc, char *argv[])
+{
+
+  if ( argc <= 1 )
+  {
+    cout << "Usage: " << argv[0] << " <dicom folder>" << endl;
+    return 1;
+  }
+
+  char* dirName = vtkTestUtilities::ExpandDataFileName( argc, argv, "Data/dicom/collection" );
+  std::string directoryName = dirName;
+  delete [] dirName;
+
+  vtkSmartPointer<vtkDICOMImageReader> DICOMReader =
+    vtkSmartPointer<vtkDICOMImageReader>::New();
+
+  // Read the input files
+  DICOMReader->SetDirectoryName(directoryName.c_str());
+  cout << "Directory name: " << DICOMReader->GetDirectoryName() << endl;
+
+  DICOMReader->Update();
+
+  // Read and display the image properties
+  const char* fileExtensions = DICOMReader->GetFileExtensions();
+  cout << "File extensions: " << fileExtensions << endl;
+
+  const char* descriptiveName = DICOMReader->GetDescriptiveName();
+  cout << "Descriptive name: " << descriptiveName << endl;
+
+  double* pixelSpacing = DICOMReader->GetPixelSpacing();
+  cout << "Pixel spacing: " << *pixelSpacing << endl;
+
+  int width = DICOMReader->GetWidth();
+  cout << "Image width: " << width << endl;
+
+  int height = DICOMReader->GetHeight();
+  cout << "Image height: " << height << endl;
+
+  float* imagePositionPatient = DICOMReader->GetImagePositionPatient();
+  cout << "Image position patient: " << *imagePositionPatient << endl;
+
+  float* imageOrientationPatient = DICOMReader->GetImageOrientationPatient();
+  cout << "Image orientation patient: " << *imageOrientationPatient << endl;
+
+  int bitsAllocated = DICOMReader->GetBitsAllocated();
+  cout << "Bits allocated: " << bitsAllocated << endl;
+
+  int pixelRepresentation = DICOMReader->GetPixelRepresentation();
+  cout << "Pixel representation: " << pixelRepresentation << endl;
+
+  int numberOfComponents = DICOMReader->GetNumberOfComponents();
+  cout << "Number of components: " << numberOfComponents << endl;
+
+  const char* transferSyntaxUID = DICOMReader->GetTransferSyntaxUID();
+  cout << "Transfer syntax UID: " << transferSyntaxUID << endl;
+
+  float rescaleSlope = DICOMReader->GetRescaleSlope();
+  cout << "Rescale slope: " << rescaleSlope << endl;
+
+  float rescaleOffset = DICOMReader->GetRescaleOffset();
+  cout << "Rescale offset: " << rescaleOffset << endl;
+
+  const char* patientName = DICOMReader->GetPatientName();
+  cout << "Patient name: " << patientName << endl;
+
+  const char* studyUID = DICOMReader->GetStudyUID();
+  cout << "Study UID: " << studyUID << endl;
+
+  const char* studyID = DICOMReader->GetStudyID();
+  cout << "Study ID: " << studyID << endl;
+
+  float gantryAngle = DICOMReader->GetGantryAngle();
+  cout << "Gantry angle: " << gantryAngle << endl;
+
+
+  // Display the center slice
+  int sliceNumber =
+    (DICOMReader->GetOutput()->GetExtent()[5] +
+     DICOMReader->GetOutput()->GetExtent()[4]) / 2;
+
+  // Visualize
+  vtkSmartPointer<vtkImageViewer2> imageViewer =
+    vtkSmartPointer<vtkImageViewer2>::New();
+  imageViewer->SetInputConnection(DICOMReader->GetOutputPort());
+  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
+    vtkSmartPointer<vtkRenderWindowInteractor>::New();
+  imageViewer->SetupInteractor(renderWindowInteractor);
+  imageViewer->SetSlice(sliceNumber);
+  imageViewer->Render();
+  imageViewer->GetRenderer()->ResetCamera();
+  renderWindowInteractor->Initialize();
+  imageViewer->Render();
+
+  renderWindowInteractor->Start();
+
+
+  return 0;
+}

IO/Image/Testing/Data/Baseline/TestDICOMImageReaderFileCollection.png.md5

@@ -0,0 +1 @@
+6c042ee4549194e7ad928446e82896b9

IO/Image/vtkDICOMImageReader.cxx

@@ -102,7 +102,7 @@ int vtkDICOMImageReader::CanReadFile(const char* fname)
   }
   else
   {
-    vtkErrorMacro("DICOMParser couldn't parse : " << fname);
+    vtkWarningMacro("DICOMParser couldn't parse : " << fname);
     return 0;
   }
 }

Testing/Data/dicom/collection/IM-0001-1983.dcm.md5

@@ -0,0 +1 @@
+3258ea5d2a205a17c47d9360c9748f5b

Testing/Data/dicom/collection/IM-0001-1984.dcm.md5

@@ -0,0 +1 @@
+07ebebd3fd24d2391a6c70655b6796f6

Testing/Data/dicom/collection/IM-0001-1985.dcm.md5

@@ -0,0 +1 @@
+8eb81359e5d950cf1afb0afe7b2371f6

Testing/Data/dicom/collection/IM-0001-1986.dcm.md5

@@ -0,0 +1 @@
+7bc8b3eeaf480aecba5d58ee83eee000

Testing/Data/dicom/collection/IM-0001-1987.dcm.md5

@@ -0,0 +1 @@
+6d68ed1fbc44a83e5edc57def951a416

Testing/Data/dicom/collection/IM-0001-1988.dcm.md5

@@ -0,0 +1 @@
+ac8befa7248e9a6a98df3a8bb02e4e3a

Testing/Data/dicom/collection/IM-0001-1989.dcm.md5

@@ -0,0 +1 @@
+ca1cfecd2cd54e34f4d6715f030b7ca7

Testing/Data/dicom/collection/IM-0001-1990.dcm.md5

@@ -0,0 +1 @@
+8bc833af0701dbf9e9e2101930ad95f8

Testing/Data/dicom/collection/IM-0001-1991.dcm.md5

@@ -0,0 +1 @@
+bfc7b2189f7f4ada15ecdbfb2416c223

Testing/Data/dicom/collection/IM-0001-1992.dcm.md5

@@ -0,0 +1 @@
+c5ca32209c7ecd151635581d97a43b81

Testing/Data/dicom/collection/IM-0001-1993.dcm.md5

@@ -0,0 +1 @@
+dc1ac27b3f31512d5863ea16e86ca634