///<summary>Deletes all static objects created</summary>
 public static void deleteAllVTKObjects()
 {
     //clean up vtk objects
     if (image1 != null)
     {
         image1.Dispose();
     }
     if (piw != null)
     {
         piw.Dispose();
     }
     if (viewer != null)
     {
         viewer.Dispose();
     }
 }