# ImageValueRange

VTKExamples/Cxx/Images/ImageValueRange

### Code

ImageValueRange.cxx

    #include <vtkVersion.h>
    #include <vtkSmartPointer.h>
    #include <vtkDoubleArray.h>
    #include <vtkImageData.h>
    #include <vtkPointData.h>

    int main(int, char *[])
    {
      // Create an image data
      vtkSmartPointer<vtkImageData> imageData = vtkSmartPointer<vtkImageData>::New();

      // Specify the size of the image data
      imageData->SetDimensions(5,1,1);
    #if VTK_MAJOR_VERSION <= 5
      imageData->SetNumberOfScalarComponents(1);
      imageData->SetScalarTypeToDouble();
      imageData->AllocateScalars();
    #else
      imageData->AllocateScalars(VTK_DOUBLE,1);
    #endif
      int* dims = imageData->GetDimensions();

      for (int x = 0; x < dims[0]; x++)
      {
        double* pixel = static_cast<double*>(imageData->GetScalarPointer(x,0,0));
        pixel[0] = x*10;
      }

      double valuesRange[2];
      vtkDoubleArray::SafeDownCast(imageData->GetPointData()->GetArray("ImageScalars"))->GetValueRange(valuesRange);
      std::cout << "valuesRange = " << valuesRange[0] << " " << valuesRange[1] << std::endl;

      // This should also work:
      // min = vtkImageData->GetOutput()->GetScalarRange()[0] and max = GetScalarRange()[1].
      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(ImageValueRange)

    find_package(VTK REQUIRED)
    include(${VTK_USE_FILE})

    add_executable(ImageValueRange MACOSX_BUNDLE ImageValueRange.cxx )

    target_link_libraries(ImageValueRange ${VTK_LIBRARIES})

### Download and Build ImageValueRange

Click here to download ImageValueRange and its CMakeLists.txt file. Once the tarball ImageValueRange.tar has been downloaded and extracted,

    cd ImageValueRange/build

If VTK is installed:

    cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

    cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

    make

and run it:

    ./ImageValueRange

WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.