Use wide paths for TIFF on Win32 for utf-8 support

IO/Image/vtkTIFFReader.cxx

@@ -8,6 +8,8 @@
 #include "vtkImageData.h"
 #include "vtkObjectFactory.h"
 #include "vtkPointData.h"
+
+#include "vtksys/Encoding.hxx"
 #include "vtksys/SystemTools.hxx"
 
 #include <algorithm>
@@ -146,7 +148,12 @@ bool vtkTIFFReader::vtkTIFFReaderInternal::Open(const char* filename)
   {
     return false;
   }
+#if defined(_WIN32)
+  std::wstring widepath = vtksys::Encoding::ToWide(filename);
+  this->Image = TIFFOpenW(widepath.c_str(), "r");
+#else
   this->Image = TIFFOpen(filename, "r");
+#endif
   if (!this->Image)
   {
     this->Clean();

IO/Image/vtkTIFFWriter.cxx

@@ -11,6 +11,8 @@
 #include "vtkStreamingDemandDrivenPipeline.h"
 #include "vtk_tiff.h"
 
+#include "vtksys/Encoding.hxx"
+
 #include <sstream>
 #include <vector>
 
@@ -160,7 +162,12 @@ void vtkTIFFWriter::WriteFileHeader(ostream*, vtkImageData* data, int wExt[6])
     // Large image detected, use BigTIFF mode
     writeMode << "8";
   }
+#if defined(_WIN32)
+  std::wstring widepath = vtksys::Encoding::ToWide(this->InternalFileName);
+  TIFF* tif = TIFFOpenW(widepath.c_str(), writeMode.str().c_str());
+#else
   TIFF* tif = TIFFOpen(this->InternalFileName, writeMode.str().c_str());
+#endif
 
   if (!tif)
   {