diff --git a/Modules/AlgorithmsExt/mitkUnstructuredGridClusteringFilter.cpp b/Modules/AlgorithmsExt/mitkUnstructuredGridClusteringFilter.cpp
index 978f10cb07..818a53a7d5 100644
--- a/Modules/AlgorithmsExt/mitkUnstructuredGridClusteringFilter.cpp
+++ b/Modules/AlgorithmsExt/mitkUnstructuredGridClusteringFilter.cpp
@@ -1,214 +1,220 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #include <mitkUnstructuredGridClusteringFilter.h>
 
 #include <vtkSmartPointer.h>
 #include <vtkPointLocator.h>
 #include <vtkPoints.h>
 #include <vtkUnstructuredGrid.h>
 #include <vtkDelaunay3D.h>
 #include <vtkPolyVertex.h>
 
 
 mitk::UnstructuredGridClusteringFilter::UnstructuredGridClusteringFilter() : m_eps(0.0), m_MinPts(0), m_Meshing(true)
 {
   this->m_UnstructGrid = mitk::UnstructuredGrid::New();
 }
 
 mitk::UnstructuredGridClusteringFilter::~UnstructuredGridClusteringFilter(){}
 
 std::map<int, bool> visited;
 std::map<int, bool> isNoise;
 std::map<int, bool> clusterMember;
 vtkSmartPointer<vtkPointLocator> pLocator;
 
 void mitk::UnstructuredGridClusteringFilter::GenerateOutputInformation()
 {
   m_UnstructGrid = this->GetOutput();
 }
 
 void mitk::UnstructuredGridClusteringFilter::GenerateData()
 {
   mitk::UnstructuredGrid::Pointer inputGrid = const_cast<mitk::UnstructuredGrid*>(this->GetInput());
   if(inputGrid.IsNull()) return;
 
   vtkSmartPointer<vtkUnstructuredGrid> vtkInpGrid = inputGrid->GetVtkUnstructuredGrid();
   vtkSmartPointer<vtkPoints> inpPoints = vtkInpGrid->GetPoints();
   pLocator =vtkSmartPointer<vtkPointLocator>::New();
   std::vector< vtkSmartPointer<vtkPoints> > clusterVector;
 
   pLocator->SetDataSet(vtkInpGrid);
   pLocator->AutomaticOn();
   pLocator->SetNumberOfPointsPerBucket(2);
   pLocator->BuildLocator();
 
   //fill the visited map with false for checking
   for(int i=0; i<inpPoints->GetNumberOfPoints();i++)
   {
     visited[i] = false;
     isNoise[i] = false;
     clusterMember[i] = false;
   }
 
   for(int i=0; i<inpPoints->GetNumberOfPoints();i++)
   {
     if(!visited[i])
     {
       visited[i] = true; //mark P as visited
       vtkSmartPointer<vtkIdList> idList = vtkSmartPointer<vtkIdList>::New(); //represent N
       pLocator->FindPointsWithinRadius(m_eps, inpPoints->GetPoint(i), idList); //N = D.regionQuery(P, eps)
       if(idList->GetNumberOfIds() < m_MinPts) //if sizeof(N) < MinPts
       {
         isNoise[i] = true; //mark P as NOISE
       }
       else
       {
         vtkSmartPointer<vtkPoints> cluster = vtkSmartPointer<vtkPoints>::New(); //represent a cluster
         clusterVector.push_back(cluster); //C = next cluster
         this->ExpandCluster(i,idList,cluster,inpPoints); //expandCluster(P, N, C, eps, MinPts) mod. the parameter list
       }
     }
   }
 
   //OUTPUT LOGIC
   m_Clusters = clusterVector;
   int numberOfClusterPoints = 0;
   int IdOfBiggestCluster = 0;
 
   for(unsigned int i=0; i<m_Clusters.size();i++)
   {
     vtkSmartPointer<vtkPoints> points = m_Clusters.at(i);
     std::cout << "CLUSTER " << i << ": " << points->GetNumberOfPoints() << std::endl;
     for(int j=0; j<points->GetNumberOfPoints();j++)
     {
       double point[3];
       points->GetPoint(j,point);
       std::cout << "POINT: " << point[0] << " " << point[1] << " " << point[2] << std::endl;
     }
     if(points->GetNumberOfPoints() > numberOfClusterPoints)
     {
       numberOfClusterPoints = points->GetNumberOfPoints();
       IdOfBiggestCluster = i;
     }
   }
 
   vtkSmartPointer<vtkUnstructuredGrid> biggestCluster = vtkSmartPointer<vtkUnstructuredGrid>::New();
 
   vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
   points = m_Clusters.at(IdOfBiggestCluster);
 
   vtkSmartPointer<vtkPolyVertex> verts = vtkSmartPointer<vtkPolyVertex>::New();
   verts->GetPointIds()->SetNumberOfIds(m_Clusters.at(IdOfBiggestCluster)->GetNumberOfPoints());
   for(int i=0; i<m_Clusters.at(IdOfBiggestCluster)->GetNumberOfPoints(); i++)
   {
     verts->GetPointIds()->SetId(i,i);
   }
 
   biggestCluster->Allocate(1);
   biggestCluster->InsertNextCell(verts->GetCellType(), verts->GetPointIds());
   biggestCluster->SetPoints(m_Clusters.at(IdOfBiggestCluster));
 
   if(m_Meshing)
   {
     vtkSmartPointer<vtkDelaunay3D> mesher = vtkSmartPointer<vtkDelaunay3D>::New();
     mesher->SetInputData(biggestCluster);
     mesher->SetAlpha(0.9);
     mesher->Update();
 
     vtkSmartPointer<vtkUnstructuredGrid> output = mesher->GetOutput();
     m_UnstructGrid->SetVtkUnstructuredGrid(output);
   }
   else
   {
     m_UnstructGrid->SetVtkUnstructuredGrid(biggestCluster);
   }
 }
 
 void mitk::UnstructuredGridClusteringFilter::ExpandCluster(int id, vtkIdList *pointIDs, vtkPoints* cluster, vtkPoints* inpPoints)
 {
   cluster->InsertNextPoint(inpPoints->GetPoint(id)); //add P to cluster C
   clusterMember[id] = true; //right?
 
   vtkSmartPointer<vtkPoints> neighbours = vtkSmartPointer<vtkPoints>::New(); //same N as in other function
   inpPoints->GetPoints(pointIDs,neighbours);
 
   for(int i=0; i<pointIDs->GetNumberOfIds();i++) //for each point P' in N
   {
     if(!visited[pointIDs->GetId(i)]) //if P' is not visited
     {
       visited[pointIDs->GetId(i)] = true; //mark P' as visited
       vtkSmartPointer<vtkIdList> idList = vtkSmartPointer<vtkIdList>::New(); //represent N'
       pLocator->FindPointsWithinRadius(m_eps, inpPoints->GetPoint(pointIDs->GetId(i)), idList); //N' = D.regionQuery(P', eps)
       if(idList->GetNumberOfIds() >= m_MinPts) //if sizeof(N') >= MinPts
       {
         for(int j=0; j<idList->GetNumberOfIds();j++) //N = N joined with N'
         {
           pointIDs->InsertNextId(idList->GetId(j));
         }
       }
     }
     if(!clusterMember[pointIDs->GetId(i)]) //if P' is not yet member of any cluster
     {
       clusterMember[pointIDs->GetId(i)] = true;
       cluster->InsertNextPoint(inpPoints->GetPoint(pointIDs->GetId(i))); //add P' to cluster C
     }
   }
 }
 
 std::vector<mitk::UnstructuredGrid::Pointer> mitk::UnstructuredGridClusteringFilter::GetAllClusters()
 {
   std::vector< mitk::UnstructuredGrid::Pointer > mitkUGridVector;
 
-  for(int i=0; i<m_Clusters.size();i++)
+  for(unsigned int i=0; i<m_Clusters.size();i++)
   {
     vtkSmartPointer<vtkUnstructuredGrid> cluster = vtkSmartPointer<vtkUnstructuredGrid>::New();
 
     vtkSmartPointer<vtkPoints> points = m_Clusters.at(i);
 
     vtkSmartPointer<vtkPolyVertex> verts = vtkSmartPointer<vtkPolyVertex>::New();
 
     verts->GetPointIds()->SetNumberOfIds(points->GetNumberOfPoints());
     for(int i=0; i<points->GetNumberOfPoints(); i++)
     {
       verts->GetPointIds()->SetId(i,i);
     }
 
     cluster->Allocate(1);
     cluster->InsertNextCell(verts->GetCellType(), verts->GetPointIds());
     cluster->SetPoints(points);
 
     mitk::UnstructuredGrid::Pointer mitkGrid = mitk::UnstructuredGrid::New();
 
     if(m_Meshing)
     {
       vtkSmartPointer<vtkDelaunay3D> mesher = vtkSmartPointer<vtkDelaunay3D>::New();
       mesher->SetInputData(cluster);
       mesher->SetAlpha(0.9);
       mesher->Update();
 
       vtkSmartPointer<vtkUnstructuredGrid> output = mesher->GetOutput();
       mitkGrid->SetVtkUnstructuredGrid(output);
     }
     else
     {
       mitkGrid->SetVtkUnstructuredGrid(cluster);
     }
 
     mitkUGridVector.push_back(mitkGrid);
-    return mitkUGridVector;
   }
+
+  return mitkUGridVector;
+}
+
+int mitk::UnstructuredGridClusteringFilter::GetNumberOfFoundClusters()
+{
+  return m_Clusters.size();
 }
diff --git a/Modules/AlgorithmsExt/mitkUnstructuredGridClusteringFilter.h b/Modules/AlgorithmsExt/mitkUnstructuredGridClusteringFilter.h
index 50908b19f3..606c18ca99 100644
--- a/Modules/AlgorithmsExt/mitkUnstructuredGridClusteringFilter.h
+++ b/Modules/AlgorithmsExt/mitkUnstructuredGridClusteringFilter.h
@@ -1,110 +1,112 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #ifndef _MITKUNSTRUCTUREDGRIDCLUSTERINGFILTER_h__
 #define _MITKUNSTRUCTUREDGRIDCLUSTERINGFILTER_h__
 
 #include <MitkAlgorithmsExtExports.h>
 
 #include <mitkCommon.h>
 
 #include <mitkUnstructuredGrid.h>
 #include <vtkSmartPointer.h>
 #include <mitkUnstructuredGridToUnstructuredGridFilter.h>
 #include <vtkIdList.h>
 #include <vtkPoints.h>
 
 
 namespace mitk {
 
    /**
    * @brief The UnstructuredGridClusteringFilter class
    *
    * DBSCAN algorithm:
    *
    *     DBSCAN(D, eps, MinPts)
    *     C = 0
    *     for each unvisited point P in dataset D
    *       mark P as visited
    *       N = D.regionQuery(P, eps)
    *       if sizeof(N) < MinPts
    *         mark P as NOISE
    *       else
    *         C = next cluster
    *         expandCluster(P, N, C, eps, MinPts)
    *
    *     expandCluster(P, N, C, eps, MinPts)
    *       add P to cluster C
    *       for each point P' in N
    *         if P' is not visited
    *           mark P' as visited
    *           N' = D.regionQuery(P', eps)
    *           if sizeof(N') >= MinPts
    *             N = N joined with N'
    *         if P' is not yet member of any cluster
    *           add P' to cluster C
    */
 
   class MitkAlgorithmsExt_EXPORT UnstructuredGridClusteringFilter
       : public UnstructuredGridToUnstructuredGridFilter
   {
     public:
 
       mitkClassMacro(UnstructuredGridClusteringFilter, UnstructuredGridToUnstructuredGridFilter)
       itkFactorylessNewMacro(Self)
       itkCloneMacro(Self)
 
       itkSetMacro(eps, double)
       itkGetMacro(eps, double)
 
       itkSetMacro(MinPts, int)
       itkGetMacro(MinPts, int)
 
       itkSetMacro(Meshing, bool)
 
       virtual std::vector< mitk::UnstructuredGrid::Pointer> GetAllClusters();
 
+      virtual int GetNumberOfFoundClusters();
+
       virtual void GenerateOutputInformation();
 
       virtual void GenerateData();
 
     protected:
 
       UnstructuredGridClusteringFilter();
 
       virtual ~UnstructuredGridClusteringFilter();
 
   private:
 
       void ExpandCluster(int id, vtkIdList* pointIDs, vtkPoints* cluster, vtkPoints *inpPoints);
 
       mitk::UnstructuredGrid::Pointer m_UnstructGrid;
 
       std::vector< vtkSmartPointer<vtkPoints> > m_Clusters;
 
       double m_eps;
 
       int m_MinPts;
 
       bool m_Meshing;
 
   };
 
 } // namespace mitk
 
 #endif //_MITKUNSTRUCTUREDGRIDCLUSTERINGFILTER_h__