diff --git a/apps/VoxelizerTool/rttbMaskWriter.cpp b/apps/VoxelizerTool/rttbMaskWriter.cpp
index 5a9c375..3593d7f 100644
--- a/apps/VoxelizerTool/rttbMaskWriter.cpp
+++ b/apps/VoxelizerTool/rttbMaskWriter.cpp
@@ -1,133 +1,133 @@
 // -----------------------------------------------------------------------
 // RTToolbox - DKFZ radiotherapy quantitative evaluation library
 //
 // Copyright (c) German Cancer Research Center (DKFZ),
 // Software development for Integrated Diagnostics and Therapy (SIDT).
 // ALL RIGHTS RESERVED.
 // See rttbCopyright.txt or
 // http://www.dkfz.de/en/sidt/projects/rttb/copyright.html
 //
 // This software is distributed WITHOUT ANY WARRANTY; without even
 // the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 // PURPOSE.  See the above copyright notices for more information.
 //
 //------------------------------------------------------------------------
 /*!
 // @file
 // @version $Revision: 1377 $ (last changed revision)
 // @date    $Date: 2016-06-07 10:26:43 +0200 (Di, 07 Jun 2016) $ (last change date)
 // @author  $Author: strubel $ (last changed by)
 */
 #include "rttbMaskWriter.h"
 
 #include "itkImage.h"
 #include "itkImageFileWriter.h"
 #include "itkBinaryThresholdImageFilter.h"
 #include "itkAddImageFilter.h"
 
 namespace rttb
 {
 	namespace apps
 	{
 		namespace voxelizerTool
 		{
 			MaskWriter::MaskWriter(std::vector<MaskAccessorPointer> maskPointer,
 			                       bool voxelization) : _maskPointerVector(maskPointer), _booleanvoxelization(voxelization)
 			{
 			}
 
 			void MaskWriter::writeMaskToFile(const std::string& outputFileName) const
 			{
 				if (!_maskPointerVector.empty())
 				{
 					ITKImageTypeConstPointer itkImage;
 
 					if (_maskPointerVector.size() > 1)
 					{
 						itkImage = addMultipleStructsToImage();
 					}
 					else
 					{
 						io::itk::ITKImageMaskAccessorConverter maskAccessorConverter(_maskPointerVector.at(0));
 						maskAccessorConverter.process();
 						itkImage = maskAccessorConverter.getITKImage();
 					}
 
 					if (_booleanvoxelization)
 					{
 						itkImage = applyThresholdFilter(itkImage);
 					}
 
-					writeITKImageToFile(itkImage, outputFileName);
+					writeITKImageToFile(itkImage, outputFileName, true);
 				}
 			}
 
 			MaskWriter::ITKImageTypeConstPointer MaskWriter::addMultipleStructsToImage() const
 			{
 				std::vector<ITKImageTypePointer> listOfITKImages;
 
 				for (int i = 0; i < _maskPointerVector.size(); i++)
 				{
 					io::itk::ITKImageMaskAccessorConverter maskAccessorConverter(_maskPointerVector.at(i));
 					maskAccessorConverter.process();
 					listOfITKImages.push_back(maskAccessorConverter.getITKImage());
 				}
 
 				typedef itk::AddImageFilter <ITKMaskImageType, ITKMaskImageType>AddImageFilterType;
 
 				AddImageFilterType::Pointer addFilter = AddImageFilterType::New();
 				ITKImageTypePointer filterResult;
 
 				for (int k = 1; k < listOfITKImages.size(); k++)
 				{
 					if (k == 1)
 					{
 						addFilter->SetInput1(listOfITKImages.at(0));
 					}
 					else
 					{
 						addFilter->SetInput1(filterResult);
 					}
 
 					addFilter->SetInput2(listOfITKImages.at(k));
 
 					addFilter->Update();
 
 					filterResult = addFilter->GetOutput();
 				}
 
 				ITKImageTypeConstPointer filterResultConst(filterResult);
 				return filterResultConst;
 			}
 
 			MaskWriter::ITKImageTypeConstPointer MaskWriter::applyThresholdFilter(
 			    ITKImageTypeConstPointer itkImage) const
 			{
 
 				typedef itk::BinaryThresholdImageFilter< ITKMaskImageType, ITKMaskImageType >  FilterType;
 				FilterType::Pointer filter = FilterType::New();
 
 				filter->SetInput(itkImage);
 				filter->SetLowerThreshold(0.5);
 				filter->SetUpperThreshold(1.0);
 				filter->SetInsideValue(1.0);
 
 				filter->Update();
 
 				return filter->GetOutput();
 			}
 
 			void MaskWriter::writeITKImageToFile(ITKImageTypeConstPointer itkImage,
 			                                     const std::string& outputfilename, bool useCompression) const
 			{
 				typedef  itk::ImageFileWriter< ITKMaskImageType > WriterType;
 				WriterType::Pointer writer = WriterType::New();
 				writer->SetFileName(outputfilename);
 				writer->SetUseCompression(useCompression);
 				writer->SetInput(itkImage);
 
 				writer->Update();
 			}
 		}
 	}
 }