Only apply NoDataValue when it is set in the input image

Also explicitly cast NoDataValue to GDAL data type
Include test based on USGS elevation data

IO/GDAL/Testing/Cxx/CMakeLists.txt

+set(TestGDALRasterNoDataValue_ARGS
+  -D DATA{../Data/Input/TestGDALRasterNoDataValue.tif}
+)
+
 vtk_add_test_cxx(${vtk-module}CxxTests tests
   TestGDALVectorReader.cxx
   TestGDALRasterReader.cxx
+  TestGDALRasterNoDataValue.cxx,NO_VALID,NO_OUTPUT
   )
 vtk_test_cxx_executable(${vtk-module}CxxTests tests)

IO/GDAL/Testing/Cxx/TestGDALRasterNoDataValue.cxx

+/*=========================================================================
+
+  Program:   Visualization Toolkit
+  Module:    TestGDALRasterReader.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.
+
+=========================================================================*/
+#include <vtkGDALRasterReader.h>
+#include <vtkNew.h>
+#include <vtkUniformGrid.h>
+
+#include <iostream>
+
+// Main program
+int TestGDALRasterNoDataValue(int argc, char** argv)
+{
+  if (argc < 3)
+    {
+    std::cerr << "Expected TestName -D InputFile.tif";
+    return -1;
+    }
+
+  std::string inputFileName(argv[2]);
+
+  // Create reader to read shape file.
+  vtkNew<vtkGDALRasterReader> reader;
+  reader->SetFileName(inputFileName.c_str());
+  reader->Update();
+
+  vtkUniformGrid *rasterImage = vtkUniformGrid::SafeDownCast(
+    reader->GetOutput());
+
+  int numErrors = 0;
+
+  if (!rasterImage->HasAnyBlankPoints())
+    {
+    std::cerr << "Error image has no blank points" << std::endl;
+    ++numErrors;
+    }
+
+  if (!rasterImage->HasAnyBlankCells())
+    {
+    std::cerr << "Error image has no blank cells" << std::endl;
+    ++numErrors;
+    }
+
+  double *scalarRange = rasterImage->GetScalarRange();
+
+  if ((scalarRange[0] < -888.5) || (scalarRange[0]) > -887.5)
+    {
+    std::cerr << "Error scalarRange[0] should be -888.0, not "
+              << scalarRange[0] << std::endl;
+    ++numErrors;
+    }
+
+  if ((scalarRange[1] < 9998.5) || (scalarRange[1] > 9999.5))
+    {
+    std::cerr << "Error scalarRange[1] should be 9999.0, not "
+              << scalarRange[1] << std::endl;
+    ++numErrors;
+    }
+
+  //std::cout << "numErrors: " << numErrors << std::endl;
+  return numErrors;
+}

IO/GDAL/Testing/Data/Input/TestGDALRasterNoDataValue.tif.md5

+f73cb0b2de8941d9e491190d193f10a2

IO/GDAL/vtkGDALRasterReader.cxx

@@ -101,6 +101,7 @@ public:
   // Upper left, lower left, upper right, lower right
   double CornerPoints[8];
 
+  int HasNoDataValue;
   double NoDataValue;
   vtkIdType NumberOfPoints;
 
@@ -287,7 +288,8 @@ void vtkGDALRasterReader::vtkGDALRasterReaderInternal::GenericReadData()
   for (int i = 1; i <= this->NumberOfBands; ++i)
     {
     GDALRasterBand* rasterBand = this->GDALData->GetRasterBand(i);
-    NoDataValue = rasterBand->GetNoDataValue();
+    this->HasNoDataValue = 0;
+    this->NoDataValue = rasterBand->GetNoDataValue(&this->HasNoDataValue);
     if (this->NumberOfBytesPerPixel == 0)
       {
       this->TargetDataType = rasterBand->GetRasterDataType();
@@ -480,6 +482,12 @@ void vtkGDALRasterReader::vtkGDALRasterReaderInternal::Convert(
   scArr->SetNumberOfComponents(this->NumberOfBands);
   scArr->SetNumberOfTuples(targetWidth * targetHeight);
 
+  RAW_TYPE TNoDataValue = 0;
+  if (this->HasNoDataValue)
+    {
+    TNoDataValue = static_cast<RAW_TYPE>(this->NoDataValue);
+    }
+
   for (int j = 0; j < targetHeight; ++j)
     {
     for (int i = 0; i < targetWidth; ++i)
@@ -491,11 +499,18 @@ void vtkGDALRasterReader::vtkGDALRasterReaderInternal::Convert(
                       j * targetWidth * NumberOfBands + bandIndex;
         sourceIndex = i + j * targetWidth +
                       bandIndex * targetWidth * targetHeight;
+
         RAW_TYPE tmp = rawUniformGridData[sourceIndex];
-        if(tmp < min) min = tmp;
-        if(tmp > max) max = tmp;
-        if(tmp == NoDataValue) this->UniformGridData->BlankPoint(targetIndex);
-        else this->NumberOfPoints++;
+        if (this->HasNoDataValue && tmp == TNoDataValue)
+          {
+          this->UniformGridData->BlankPoint(targetIndex);
+          }
+        else
+          {
+          if(tmp < min) min = tmp;
+          if(tmp > max) max = tmp;
+          this->NumberOfPoints++;
+          }
 
         scArr->InsertValue(targetIndex, rawUniformGridData[sourceIndex]);
         }