diff --git a/src/buildblock/ProjData.cxx b/src/buildblock/ProjData.cxx
index 0a8067fe8..9ee604d75 100644
--- a/src/buildblock/ProjData.cxx
+++ b/src/buildblock/ProjData.cxx
@@ -58,7 +58,7 @@
 #include "stir/IO/GEHDF5Wrapper.h"
 #endif
 #include "stir/IO/stir_ecat7.h"
-#include "stir/ViewSegmentNumbers.h"
+#include "stir/ViewgramIndices.h"
 #include "stir/is_null_ptr.h"
 #include <cstring>
 #include <fstream>
@@ -261,7 +261,19 @@ ProjData::get_subset(const std::vector<int>& views) const
 }
 
   
-Viewgram<float> 
+Viewgram<float>
+ProjData::get_empty_viewgram(const ViewgramIndices& ind) const
+{
+  return proj_data_info_sptr->get_empty_viewgram(ind);
+}
+
+Sinogram<float>
+ProjData::get_empty_sinogram(const SinogramIndices& ind) const
+{
+  return proj_data_info_sptr->get_empty_sinogram(ind);
+}
+
+Viewgram<float>
 ProjData::get_empty_viewgram(const int view_num, const int segment_num, 
 			     const bool make_num_tangential_poss_odd) const
 {
@@ -297,7 +309,7 @@ ProjData::get_empty_segment_by_view(const int segment_num,
 }
 
 RelatedViewgrams<float> 
-ProjData::get_empty_related_viewgrams(const ViewSegmentNumbers& view_segmnet_num,
+ProjData::get_empty_related_viewgrams(const ViewgramIndices& view_segmnet_num,
                    //const int view_num, const int segment_num,
 		   const shared_ptr<DataSymmetriesForViewSegmentNumbers>& symmetries_used,
 		   const bool make_num_tangential_poss_odd) const
@@ -308,15 +320,14 @@ ProjData::get_empty_related_viewgrams(const ViewSegmentNumbers& view_segmnet_num
 
 
 RelatedViewgrams<float> 
-ProjData::get_related_viewgrams(const ViewSegmentNumbers& view_segmnet_num,
-                   //const int view_num, const int segment_num,
+ProjData::get_related_viewgrams(const ViewgramIndices& viewgram_indices,
 		   const shared_ptr<DataSymmetriesForViewSegmentNumbers>& symmetries_used,
 		   const bool make_num_bins_odd) const
 {
   vector<ViewSegmentNumbers> pairs;
   symmetries_used->get_related_view_segment_numbers(
     pairs, 
-    ViewSegmentNumbers(view_segmnet_num.view_num(),view_segmnet_num.segment_num())
+    viewgram_indices
     );
 
   vector<Viewgram<float> > viewgrams;
diff --git a/src/buildblock/ProjDataInfo.cxx b/src/buildblock/ProjDataInfo.cxx
index 4b5bfc87c..0a0823dc8 100644
--- a/src/buildblock/ProjDataInfo.cxx
+++ b/src/buildblock/ProjDataInfo.cxx
@@ -4,7 +4,7 @@
     Copyright (C) 2000 PARAPET partners
     Copyright (C) 2000 - 2009-05-13, Hammersmith Imanet Ltd
     Copyright (C) 2011-07-01 - 2011, Kris Thielemans
-    Copyright (C) 2018, 2022, University College London
+    Copyright (C) 2018, 2022, 2023, University College London
     Copyright (C) 2018, University of Leeds
     This file is part of STIR.
 
@@ -262,6 +262,15 @@ ProjDataInfo::get_empty_viewgram(const int view_num,
   return v;
 }
 
+Viewgram<float> 
+ProjDataInfo::get_empty_viewgram(const ViewgramIndices& ind) const
+{  
+  // we can't access the shared ptr, so we have to clone 'this'.
+  shared_ptr<ProjDataInfo>  proj_data_info_sptr(this->clone());
+  Viewgram<float> v(proj_data_info_sptr, ind);
+  return v;
+}
+
 
 Sinogram<float>
 ProjDataInfo::get_empty_sinogram(const int axial_pos_num, const int segment_num,
@@ -278,6 +287,15 @@ ProjDataInfo::get_empty_sinogram(const int axial_pos_num, const int segment_num,
   return s;
 }
 
+Sinogram<float>
+ProjDataInfo::get_empty_sinogram(const SinogramIndices& ind) const
+{
+  // we can't access the shared ptr, so we have to clone 'this'.
+  shared_ptr<ProjDataInfo>  proj_data_info_sptr(this->clone());
+  Sinogram<float> s(proj_data_info_sptr, ind);
+  return s;
+}
+
 SegmentBySinogram<float>
 ProjDataInfo::get_empty_segment_by_sinogram(const int segment_num, 
       const bool make_num_tangential_poss_odd) const
@@ -296,6 +314,14 @@ ProjDataInfo::get_empty_segment_by_sinogram(const int segment_num,
   return s;
 }  
 
+SegmentBySinogram<float>
+ProjDataInfo::get_empty_segment_by_sinogram(const SegmentIndices& ind) const
+{
+  // we can't access the shared ptr, so we have to clone 'this'.
+  shared_ptr<ProjDataInfo>  proj_data_info_sptr(this->clone());
+  SegmentBySinogram<float> s(proj_data_info_sptr, ind);
+  return s;
+}
 
 SegmentByView<float>
 ProjDataInfo::get_empty_segment_by_view(const int segment_num, 
@@ -315,17 +341,24 @@ ProjDataInfo::get_empty_segment_by_view(const int segment_num,
   return s;
 }
 
+SegmentByView<float>
+ProjDataInfo::get_empty_segment_by_view(const SegmentIndices& ind) const
+{
+  // we can't access the shared ptr, so we have to clone 'this'.
+  shared_ptr<ProjDataInfo>  proj_data_info_sptr(this->clone());
+  SegmentByView<float> s(proj_data_info_sptr, ind);
+  return s;
+}
+
 RelatedViewgrams<float> 
-ProjDataInfo::get_empty_related_viewgrams(const ViewSegmentNumbers& view_segmnet_num,
-                   //const int view_num, const int segment_num,
+ProjDataInfo::get_empty_related_viewgrams(const ViewgramIndices& viewgram_indices,
 		   const shared_ptr<DataSymmetriesForViewSegmentNumbers>& symmetries_used,
 		   const bool make_num_tangential_poss_odd) const
 {
+  if (make_num_tangential_poss_odd)
+    error("make_num_tangential_poss_odd is no longer supported");
   vector<ViewSegmentNumbers> pairs;
-  symmetries_used->get_related_view_segment_numbers(
-                                                    pairs, 
-                                                    ViewSegmentNumbers(view_segmnet_num.view_num(),view_segmnet_num.segment_num())
-    );
+  symmetries_used->get_related_view_segment_numbers(pairs, viewgram_indices);
 
   vector<Viewgram<float> > viewgrams;
   viewgrams.reserve(pairs.size());
@@ -333,8 +366,7 @@ ProjDataInfo::get_empty_related_viewgrams(const ViewSegmentNumbers& view_segmnet
   for (unsigned int i=0; i<pairs.size(); i++)
   {
     // TODO optimise to get shared proj_data_info_ptr
-    viewgrams.push_back(get_empty_viewgram(pairs[i].view_num(),
-                                          pairs[i].segment_num(), make_num_tangential_poss_odd));
+    viewgrams.push_back(get_empty_viewgram(pairs[i]));
   }
 
   return RelatedViewgrams<float>(viewgrams, symmetries_used);
diff --git a/src/buildblock/SegmentBySinogram.cxx b/src/buildblock/SegmentBySinogram.cxx
index 88a53d460..336790a97 100644
--- a/src/buildblock/SegmentBySinogram.cxx
+++ b/src/buildblock/SegmentBySinogram.cxx
@@ -35,15 +35,15 @@ template <typename elemT>
 SegmentBySinogram<elemT> ::
 SegmentBySinogram(const Array<3,elemT>& v, 
 		  const shared_ptr<const ProjDataInfo>& pdi_ptr,
-		  const int segment_num)
+		  const SegmentIndices& ind)
   : 
-  Segment<elemT>(pdi_ptr, segment_num), 
+  Segment<elemT>(pdi_ptr, ind),
   Array<3,elemT>(v)
 {
   assert( get_min_view_num() == pdi_ptr->get_min_view_num());
   assert( get_max_view_num() == pdi_ptr->get_max_view_num());
-  assert( get_min_axial_pos_num() == pdi_ptr->get_min_axial_pos_num(segment_num));
-  assert( get_max_axial_pos_num() == pdi_ptr->get_max_axial_pos_num(segment_num));
+  assert( get_min_axial_pos_num() == pdi_ptr->get_min_axial_pos_num(ind.segment_num()));
+  assert( get_max_axial_pos_num() == pdi_ptr->get_max_axial_pos_num(ind.segment_num()));
   assert( get_min_tangential_pos_num() == pdi_ptr->get_min_tangential_pos_num());
   assert( get_max_tangential_pos_num() == pdi_ptr->get_max_tangential_pos_num());
 }
@@ -51,22 +51,39 @@ SegmentBySinogram(const Array<3,elemT>& v,
 template <typename elemT>  
 SegmentBySinogram<elemT> ::
 SegmentBySinogram(const shared_ptr<const ProjDataInfo>& pdi_ptr,
-		  const int segment_num)
+		  const SegmentIndices& ind)
   : 
-  Segment<elemT>(pdi_ptr, segment_num), 
-  Array<3,elemT>(IndexRange3D(pdi_ptr->get_min_axial_pos_num(segment_num),
-                              pdi_ptr->get_max_axial_pos_num(segment_num),
+  Segment<elemT>(pdi_ptr, ind),
+  Array<3,elemT>(IndexRange3D(pdi_ptr->get_min_axial_pos_num(ind.segment_num()),
+                              pdi_ptr->get_max_axial_pos_num(ind.segment_num()),
                               pdi_ptr->get_min_view_num(),
                               pdi_ptr->get_max_view_num(),
                               pdi_ptr->get_min_tangential_pos_num(),
                               pdi_ptr->get_max_tangential_pos_num()))
 {}
 
+template <typename elemT>
+SegmentBySinogram<elemT>::
+SegmentBySinogram(const Array<3,elemT>& v,
+		  const shared_ptr<const ProjDataInfo>& pdi_sptr,
+		  int segment_num)
+  :
+  SegmentBySinogram(v, pdi_sptr, SegmentIndices(segment_num))
+{}
+
+template <typename elemT>
+SegmentBySinogram<elemT>::
+SegmentBySinogram(const shared_ptr<const ProjDataInfo>& pdi_sptr,
+		  const int segment_num)
+  :
+  SegmentBySinogram(pdi_sptr, SegmentIndices(segment_num))
+{}
+
 template <typename elemT>
 SegmentBySinogram<elemT>::
 SegmentBySinogram(const SegmentByView<elemT>& s_v )
   : Segment<elemT>(s_v.get_proj_data_info_sptr()->create_shared_clone(),
-                   s_v.get_segment_num()),	      
+                   s_v.get_segment_indices()),
    Array<3,elemT> (IndexRange3D (s_v.get_min_axial_pos_num(), s_v.get_max_axial_pos_num(),
 		                 s_v.get_min_view_num(), s_v.get_max_view_num(),
 		                 s_v.get_min_tangential_pos_num(), s_v.get_max_tangential_pos_num()))
diff --git a/src/buildblock/SegmentByView.cxx b/src/buildblock/SegmentByView.cxx
index 554323988..f08fc61ae 100644
--- a/src/buildblock/SegmentByView.cxx
+++ b/src/buildblock/SegmentByView.cxx
@@ -33,15 +33,15 @@ template <typename elemT>
 SegmentByView<elemT>::
 SegmentByView(const Array<3,elemT>& v,  
               const shared_ptr<const ProjDataInfo>& pdi_ptr, 
-              const int segment_num)
+              const SegmentIndices& ind)
   :
-  Segment<elemT>(pdi_ptr, segment_num), 
+  Segment<elemT>(pdi_ptr, ind),
   Array<3,elemT>(v)
 {
   assert( get_min_view_num() == pdi_ptr->get_min_view_num());
   assert( get_max_view_num() == pdi_ptr->get_max_view_num());
-  assert( get_min_axial_pos_num() == pdi_ptr->get_min_axial_pos_num(segment_num));
-  assert( get_max_axial_pos_num() == pdi_ptr->get_max_axial_pos_num(segment_num));
+  assert( get_min_axial_pos_num() == pdi_ptr->get_min_axial_pos_num(ind.segment_num()));
+  assert( get_max_axial_pos_num() == pdi_ptr->get_max_axial_pos_num(ind.segment_num()));
   assert( get_min_tangential_pos_num() == pdi_ptr->get_min_tangential_pos_num());
   assert( get_max_tangential_pos_num() == pdi_ptr->get_max_tangential_pos_num());
 
@@ -50,22 +50,37 @@ SegmentByView(const Array<3,elemT>& v,
 template <typename elemT>
 SegmentByView<elemT>::
 SegmentByView(const shared_ptr<const ProjDataInfo>& pdi_ptr,
-              const int segment_num)
+              const SegmentIndices& ind)
   :
-  Segment<elemT>(pdi_ptr, segment_num),
+  Segment<elemT>(pdi_ptr, ind),
   Array<3,elemT>(IndexRange3D(pdi_ptr->get_min_view_num(),
                               pdi_ptr->get_max_view_num(),
-		              pdi_ptr->get_min_axial_pos_num(segment_num),
-                              pdi_ptr->get_max_axial_pos_num(segment_num),
+		              pdi_ptr->get_min_axial_pos_num(ind.segment_num()),
+                              pdi_ptr->get_max_axial_pos_num(ind.segment_num()),
 		              pdi_ptr->get_min_tangential_pos_num(),
                               pdi_ptr->get_max_tangential_pos_num()))
 {}
 
+template <typename elemT>
+SegmentByView<elemT>::
+SegmentByView(const Array<3,elemT>& v,
+              const shared_ptr<const ProjDataInfo>& pdi_sptr,
+              const int segment_num)
+  :
+  SegmentByView(v, pdi_sptr, SegmentIndices(segment_num))
+{}
+
+template <typename elemT>
+SegmentByView<elemT>::
+SegmentByView(const shared_ptr<const ProjDataInfo>& pdi_sptr,
+              const int segment_num)
+  : SegmentByView(pdi_sptr, SegmentIndices(segment_num))
+{}
+
 template <typename elemT>
 SegmentByView<elemT>::SegmentByView(const SegmentBySinogram<elemT>& s_s)
   : Segment<elemT>(s_s.get_proj_data_info_sptr()->create_shared_clone(),
-            s_s.get_segment_num()), 
-	       
+                   s_s.get_segment_indices()),
     Array<3,elemT> (IndexRange3D(s_s.get_min_view_num(),s_s.get_max_view_num(),
 		                 s_s.get_min_axial_pos_num(),s_s.get_max_axial_pos_num(),
 		                 s_s.get_min_tangential_pos_num(), s_s.get_max_tangential_pos_num()))
diff --git a/src/include/stir/ProjData.h b/src/include/stir/ProjData.h
index 722c045ac..baab84653 100644
--- a/src/include/stir/ProjData.h
+++ b/src/include/stir/ProjData.h
@@ -44,7 +44,6 @@ template <typename elemT> class SegmentBySinogram;
 template <typename elemT> class SegmentByView;
 template <typename elemT> class Viewgram;
 template <typename elemT> class Sinogram;
-class ViewSegmentNumbers;
 class Succeeded;
 class ProjDataInMemory;
 //class ExamInfo;
@@ -119,14 +118,21 @@ class ProjData : public ExamData
   inline shared_ptr<const ProjDataInfo>
     get_proj_data_info_sptr() const;
   //! Get viewgram
+  /*!
+    \deprecated Use get_viewgram(const ViewgramIndices&) instead.
+   */
   virtual Viewgram<float> 
     get_viewgram(const int view, const int segment_num,const bool make_num_tangential_poss_odd = false) const=0;
+  //! Get viewgram
   inline Viewgram<float> 
   get_viewgram(const ViewgramIndices&);
   //! Set viewgram
   virtual Succeeded 
     set_viewgram(const Viewgram<float>&) = 0;
   //! Get sinogram
+  /*!
+    \deprecated Use get_sinogram(const SinogramIndices&) instead .
+   */
   virtual Sinogram<float> 
     get_sinogram(const int ax_pos_num, const int segment_num,const bool make_num_tangential_poss_odd = false) const=0;
   //! Get sinogram
@@ -141,34 +147,66 @@ class ProjData : public ExamData
     get_subset(const std::vector<int>& views) const;
 
   //! Get empty viewgram
+  Viewgram<float> get_empty_viewgram(const ViewgramIndices&) const;
+
+  //! Get empty viewgram
+  /*!
+    \deprecated Use get_viewgram(const ViewgramIndices&) instead.
+   */
   Viewgram<float> get_empty_viewgram(const int view, const int segment_num, 
     const bool make_num_tangential_poss_odd = false) const;
   
   //! Get empty_sinogram
+  Sinogram<float> 
+    get_empty_sinogram(const SinogramIndices&) const;
+
+  //! Get empty_sinogram
+  /*!
+    \deprecated Use get_sinogram(const SinogramIndices&) instead .
+   */
   Sinogram<float> 
     get_empty_sinogram(const int ax_pos_num, const int segment_num,
     const bool make_num_tangential_poss_odd = false) const;
 
-   //! Get empty segment sino
+   //! Get empty segment by view
+  SegmentByView<float> 
+  get_empty_segment_by_view(const SegmentIndices&) const;
+  //! Get empty segment by sino
+  SegmentBySinogram<float> 
+    get_empty_segment_by_sinogram(const SegmentIndices&) const;
+  //! Get empty segment view
+  /*!
+    \deprecated Use get_empty_segment_by_sinogram(const SegmentIndices&) instead .
+   */
   SegmentByView<float> 
     get_empty_segment_by_view(const int segment_num, 
 		  	   const bool make_num_tangential_poss_odd = false) const;
-  //! Get empty segment view
+  //! Get empty segment sino
+  /*!
+    \deprecated Use get_empty_segment_by_sinogram(const SegmentIndices&) instead .
+   */
   SegmentBySinogram<float> 
     get_empty_segment_by_sinogram(const int segment_num, 
 				   const bool make_num_tangential_poss_odd = false) const;
 
-
   //! Get segment by sinogram
+  /*!
+    \deprecated Use get_segment_by_sinogram(const SegmentIndices&) instead.
+  */
   virtual SegmentBySinogram<float>
     get_segment_by_sinogram(const int segment_num) const;
 
+  //! Get segment by sinogram
   inline SegmentBySinogram<float>
     get_segment_by_sinogram(const SegmentIndices&) const;
 
   //! Get segment by view
+  /*!
+    \deprecated Use get_segment_by_view(const SegmentIndices&) instead.
+  */
   virtual SegmentByView<float> 
     get_segment_by_view(const int segment_num) const;
+  //! Get segment by view
   inline SegmentByView<float>
     get_segment_by_view(const SegmentIndices&) const;
 
@@ -181,7 +219,7 @@ class ProjData : public ExamData
 
   //! Get related viewgrams
   virtual RelatedViewgrams<float> 
-    get_related_viewgrams(const ViewSegmentNumbers&,
+    get_related_viewgrams(const ViewgramIndices&,
     const shared_ptr<DataSymmetriesForViewSegmentNumbers>&,
     const bool make_num_tangential_poss_odd = false) const;
   //! Set related viewgrams
@@ -190,7 +228,7 @@ class ProjData : public ExamData
 
   //! Get empty related viewgrams, where the symmetries_ptr specifies the symmetries to use
   RelatedViewgrams<float> 
-    get_empty_related_viewgrams(const ViewSegmentNumbers& view_segmnet_num,
+    get_empty_related_viewgrams(const ViewgramIndices& view_segmnet_num,
     //const int view_num, const int segment_num, 
     const shared_ptr<DataSymmetriesForViewSegmentNumbers>& symmetries_ptr,
     const bool make_num_tangential_poss_odd = false) const;   
diff --git a/src/include/stir/ProjDataInfo.h b/src/include/stir/ProjDataInfo.h
index 64d96cc67..d0be14fb3 100644
--- a/src/include/stir/ProjDataInfo.h
+++ b/src/include/stir/ProjDataInfo.h
@@ -4,7 +4,7 @@
     Copyright (C) 2000 PARAPET partners
     Copyright (C) 2000 - 2011-10-14, Hammersmith Imanet Ltd
     Copyright (C) 2011-07-01 - 2011, Kris Thielemans
-    Copyright (C) 2017-2018, 2020, 2022, University College London
+    Copyright (C) 2017-2018, 2020, 2022, 2023 University College London
     This file is part of STIR.
 
     SPDX-License-Identifier: Apache-2.0 AND License-ref-PARAPET-license
@@ -24,6 +24,9 @@
 #ifndef __stir_ProjDataInfo_H__
 #define __stir_ProjDataInfo_H__
 
+#include "stir/SegmentIndices.h"
+#include "stir/ViewgramIndices.h"
+#include "stir/SinogramIndices.h"
 #include "stir/VectorWithOffset.h"
 #include "stir/Scanner.h"
 #include "stir/shared_ptr.h"
@@ -347,23 +350,37 @@ class ProjDataInfo
   //@{
 
   //! Get empty viewgram
+  Viewgram<float> get_empty_viewgram(const ViewgramIndices&) const;
+  //! Get empty_sinogram
+  Sinogram<float> get_empty_sinogram(const SinogramIndices&) const;
+  //! Get empty segment sino
+  SegmentByView<float> get_empty_segment_by_view(const SegmentIndices&) const;
+  //! Get empty segment view
+  SegmentBySinogram<float> get_empty_segment_by_sinogram(const SegmentIndices&) const;
+
+  //! Get empty viewgram
+  /*! \deprecated */
   Viewgram<float> get_empty_viewgram(const int view_num, const int segment_num, 
     const bool make_num_tangential_poss_odd = false) const;
   
   //! Get empty_sinogram
+  /*! \deprecated */
   Sinogram<float> get_empty_sinogram(const int ax_pos_num, const int segment_num,
     const bool make_num_tangential_poss_odd = false) const;
 
   //! Get empty segment sino
+  /*! \deprecated */
   SegmentByView<float> get_empty_segment_by_view(const int segment_num, 
 		  	   const bool make_num_tangential_poss_odd = false) const;
   //! Get empty segment view
+  /*! \deprecated */
   SegmentBySinogram<float> get_empty_segment_by_sinogram(const int segment_num, 
 				   const bool make_num_tangential_poss_odd = false) const;
 
 
   //! Get empty related viewgrams, where the symmetries_ptr specifies the symmetries to use
-  RelatedViewgrams<float> get_empty_related_viewgrams(const ViewSegmentNumbers&,
+  /*! make_num_tangential_poss_odd has to be \c false */
+  RelatedViewgrams<float> get_empty_related_viewgrams(const ViewgramIndices&,
     const shared_ptr<DataSymmetriesForViewSegmentNumbers>&,
     const bool make_num_tangential_poss_odd = false) const;   
   //@}
diff --git a/src/include/stir/RelatedViewgrams.h b/src/include/stir/RelatedViewgrams.h
index 52742b642..7ad3847bf 100644
--- a/src/include/stir/RelatedViewgrams.h
+++ b/src/include/stir/RelatedViewgrams.h
@@ -85,8 +85,11 @@ class RelatedViewgrams
   /*! see DataSymmetriesForViewSegmentNumbers for definition of 'basic' */
   inline int get_basic_segment_num() const;
   //! get 'basic' view_segment_num
+  /*! \deprecated Use get_basic_viewgram_indices() instead. */
+  inline ViewgramIndices get_basic_view_segment_num() const;
+  //! get 'basic' viewgram indices
   /*! see DataSymmetriesForViewSegmentNumbers for definition of 'basic' */
-  inline ViewSegmentNumbers get_basic_view_segment_num() const;
+  inline ViewgramIndices get_basic_viewgram_indices() const;
 
   //! returns the number of viewgrams in this object
   inline int get_num_viewgrams() const;
diff --git a/src/include/stir/RelatedViewgrams.inl b/src/include/stir/RelatedViewgrams.inl
index 084cc68da..6eee8108f 100644
--- a/src/include/stir/RelatedViewgrams.inl
+++ b/src/include/stir/RelatedViewgrams.inl
@@ -71,10 +71,21 @@ int RelatedViewgrams<elemT>::get_basic_segment_num() const
 }
 
 template <typename elemT>
-ViewSegmentNumbers RelatedViewgrams<elemT>::
+ViewgramIndices
+RelatedViewgrams<elemT>::
+get_basic_viewgram_indices() const
+{
+  assert(viewgrams.size()>0);
+  check_state();
+  return viewgrams[0].get_viewgram_indices();
+}
+
+template <typename elemT>
+ViewgramIndices
+RelatedViewgrams<elemT>::
 get_basic_view_segment_num() const
 {
-  return ViewSegmentNumbers(get_basic_view_num(), get_basic_segment_num());
+  return this->get_basic_viewgram_indices();
 }
 
 template <typename elemT>
diff --git a/src/include/stir/Segment.h b/src/include/stir/Segment.h
index 5583ff400..7b700e752 100644
--- a/src/include/stir/Segment.h
+++ b/src/include/stir/Segment.h
@@ -1,6 +1,7 @@
 /*
     Copyright (C) 2000 PARAPET partners
     Copyright (C) 2000-2012 Hammersmith Imanet Ltd
+    Copyright (C) 2023, University College London
     This file is part of STIR.
 
     SPDX-License-Identifier: Apache-2.0 AND License-ref-PARAPET-license
@@ -21,6 +22,7 @@
 
 
 #include "stir/ProjDataInfo.h" 
+#include "stir/SegmentIndices.h"
 #include "stir/shared_ptr.h"
 
 START_NAMESPACE_STIR
@@ -33,7 +35,7 @@ template <typename elemT> class Viewgram;
   \ingroup projdata
 
   This stores a subset of the data accessible via a ProjData object,
-  where the segment_num is fixed.
+  where the SegmentIndices are fixed.
 
   At the moment, 2 'storage modes' are supported (and implemented as
   derived classes).
@@ -60,6 +62,7 @@ class Segment
     get_proj_data_info_sptr() const;
 
   virtual StorageOrder get_storage_order() const = 0;
+  inline SegmentIndices get_segment_indices() const;
   //! Get the segment number
   inline int get_segment_num() const;
   virtual int get_min_axial_pos_num() const = 0;
@@ -114,9 +117,9 @@ class Segment
 
 protected:
   shared_ptr<const ProjDataInfo> proj_data_info_sptr;
-  int segment_num;
+  SegmentIndices _indices;
   
-  inline Segment(const shared_ptr<const ProjDataInfo>& proj_data_info_sptr_v,const int s_num);
+  inline Segment(const shared_ptr<const ProjDataInfo>& proj_data_info_sptr_v,const SegmentIndices&);
 };
 
 END_NAMESPACE_STIR
diff --git a/src/include/stir/Segment.inl b/src/include/stir/Segment.inl
index 7e32fe1b6..80d31d210 100644
--- a/src/include/stir/Segment.inl
+++ b/src/include/stir/Segment.inl
@@ -3,6 +3,7 @@
 /*
     Copyright (C) 2000 PARAPET partners
     Copyright (C) 2000- 2007, IRSL
+    Copyright (C) 2023, University College London
     This file is part of STIR.
 
     SPDX-License-Identifier: Apache-2.0 AND License-ref-PARAPET-license
@@ -25,16 +26,21 @@ START_NAMESPACE_STIR
 
 template <typename elemT>
 Segment<elemT>::
-Segment( const shared_ptr<const ProjDataInfo>& proj_data_info_sptr_v,const int s_num)
+Segment( const shared_ptr<const ProjDataInfo>& proj_data_info_sptr_v,const SegmentIndices& ind)
  :
  proj_data_info_sptr(proj_data_info_sptr_v),
- segment_num(s_num)
+ _indices(ind)
     {}
 
+template <typename elemT>
+SegmentIndices
+Segment<elemT>:: get_segment_indices() const
+{ return _indices; }
+
 template <typename elemT>
 int
 Segment<elemT>:: get_segment_num() const
-{ return segment_num; }
+{ return _indices.segment_num(); }
 
 template <typename elemT>
 shared_ptr<const ProjDataInfo>
diff --git a/src/include/stir/SegmentBySinogram.h b/src/include/stir/SegmentBySinogram.h
index 25c420b5f..a4c8399a6 100644
--- a/src/include/stir/SegmentBySinogram.h
+++ b/src/include/stir/SegmentBySinogram.h
@@ -3,6 +3,7 @@
 /*
     Copyright (C) 2000 PARAPET partners
     Copyright (C) 2000- 2012, Hammersmith Imanet Ltd
+    Copyright (C) 2023, University College London
     This file is part of STIR.
 
     SPDX-License-Identifier: Apache-2.0 AND License-ref-PARAPET-license
@@ -38,7 +39,7 @@ template <typename elemT> class SegmentByView;
 
 /*!
   \ingroup projdata
-  \brief A class for storing (3d) projection data with a fixed segment_num.
+  \brief A class for storing (3d) projection data with fixed SegmentIndices.
 
   Storage order is as follows:
   \code
@@ -56,11 +57,26 @@ class SegmentBySinogram : public Segment<elemT>, public Array<3,elemT>
   typedef typename Segment<elemT>::StorageOrder StorageOrder;
 
   //! Constructor that sets the data to a given 3d Array
+  SegmentBySinogram(const Array<3,elemT>& v,
+		    const shared_ptr<const ProjDataInfo>& proj_data_info_ptr_v,
+		    const SegmentIndices& ind);
+
+  //! Constructor that sets sizes via the ProjDataInfo object, initialising data to 0
+  SegmentBySinogram(const shared_ptr<const ProjDataInfo>& proj_data_info_ptr_v,
+		    const SegmentIndices& ind);
+
+  //! Constructor that sets the data to a given 3d Array
+  /*!
+    \deprecated Use version with SegmentIndices instead
+  */
   SegmentBySinogram(const Array<3,elemT>& v, 
 		    const shared_ptr<const ProjDataInfo>& proj_data_info_ptr_v,
 		    const int segment_num);
   
   //! Constructor that sets sizes via the ProjDataInfo object, initialising data to 0
+  /*!
+    \deprecated Use version with SegmentIndices instead
+  */
   SegmentBySinogram(const shared_ptr<const ProjDataInfo>& proj_data_info_ptr_v,
 		    const int segment_num);
 
diff --git a/src/include/stir/SegmentBySinogram.inl b/src/include/stir/SegmentBySinogram.inl
index 2500a7e1e..eb25fc66a 100644
--- a/src/include/stir/SegmentBySinogram.inl
+++ b/src/include/stir/SegmentBySinogram.inl
@@ -3,6 +3,7 @@
 /*
     Copyright (C) 2000 PARAPET partners
     Copyright (C) 2000- 2007, Hammersmith Imanet Ltd
+    Copyright (C) 2023, University College London
     This file is part of STIR.
 
     SPDX-License-Identifier: Apache-2.0 AND License-ref-PARAPET-license
diff --git a/src/include/stir/SegmentByView.h b/src/include/stir/SegmentByView.h
index e0e858d82..231a17246 100644
--- a/src/include/stir/SegmentByView.h
+++ b/src/include/stir/SegmentByView.h
@@ -3,6 +3,7 @@
 /*
     Copyright (C) 2000 PARAPET partners
     Copyright (C) 2000- 2007, Hammersmith Imanet Ltd
+    Copyright (C) 2023, University College London
     This file is part of STIR.
 
     SPDX-License-Identifier: Apache-2.0 AND License-ref-PARAPET-license
@@ -37,7 +38,7 @@ template <typename elemT> class Sinogram;
 
 /*!
   \ingroup projdata
-  \brief A class for storing (3d) projection data with a fixed segment_num.
+  \brief A class for storing (3d) projection data with fixed SegmentIndices.
 
   Storage order is as follows:
   \code
@@ -55,14 +56,28 @@ template <typename elemT> class SegmentByView : public Segment<elemT>, public Ar
   typedef typename Segment<elemT>::StorageOrder StorageOrder;
 
   //! Constructor that sets the data to a given 3d Array
+  SegmentByView(const Array<3,elemT>& v,
+		const shared_ptr<const ProjDataInfo>& proj_data_info_sptr,
+		const SegmentIndices&);
+
+  //! Constructor that sets sizes via the ProjDataInfo object, initialising data to 0
+  SegmentByView(const shared_ptr<const ProjDataInfo>& proj_data_info_sptr,
+		const SegmentIndices&);
+
+  //! Constructor that sets the data to a given 3d Array
+  /*!
+    \deprecated Use version with SegmentIndices instead
+  */
   SegmentByView(const Array<3,elemT>& v,  
 		const shared_ptr<const ProjDataInfo>& proj_data_info_ptr, 
 		const int segment_num);
 
   //! Constructor that sets sizes via the ProjDataInfo object, initialising data to 0
+  /*!
+    \deprecated Use version with SegmentIndices instead
+  */
   SegmentByView(const shared_ptr<const ProjDataInfo>& proj_data_info_ptr,
 		const int segment_num);
-
   
   //! Conversion from 1 storage order to the other
   SegmentByView(const SegmentBySinogram<elemT>& );
diff --git a/src/include/stir/SegmentByView.inl b/src/include/stir/SegmentByView.inl
index 2ec586ffc..d222e6a63 100644
--- a/src/include/stir/SegmentByView.inl
+++ b/src/include/stir/SegmentByView.inl
@@ -16,6 +16,7 @@
 /*
     Copyright (C) 2000 PARAPET partners
     Copyright (C) 2000- 2011, Hammersmtih Imanet Ltd
+    Copyright (C) 2023, University College London
     This file is part of STIR.
 
     SPDX-License-Identifier: Apache-2.0 AND License-ref-PARAPET-license
diff --git a/src/include/stir/Sinogram.h b/src/include/stir/Sinogram.h
index 1661c685c..f523dceb1 100644
--- a/src/include/stir/Sinogram.h
+++ b/src/include/stir/Sinogram.h
@@ -4,6 +4,7 @@
     Copyright (C) 2000 PARAPET partners
     Copyright (C) 2000 - 2007-10-08, Hammersmith Imanet Ltd
     Copyright (C) 2011-07-01 - 2012, Kris Thielemans
+    Copyright (C) 2023, University College London
     This file is part of STIR.
 
     SPDX-License-Identifier: Apache-2.0 AND License-ref-PARAPET-license
@@ -29,6 +30,7 @@
 
 #include "stir/Array.h"
 #include "stir/ProjDataInfo.h" 
+#include "stir/SinogramIndices.h"
 #include "stir/shared_ptr.h"
 
 
@@ -40,7 +42,7 @@ START_NAMESPACE_STIR
   \ingroup projdata
   \brief A class for 2d projection data.
 
-  This represents a subset of the full projection. segment_num and axial_pos_num 
+  This represents a subset of the full projection. SegmentIndices and axial_pos_num 
   are fixed.
   
 */
@@ -60,14 +62,30 @@ class Sinogram : public Array<2,elemT>
 #endif
 
 public:
-  //! Construct sinogram from proj_data_info pointer, ring and segment number.  Data are set to 0.
+  //! Construct sinogram from proj_data_info pointe and indices.  Data are set to 0.
+  inline Sinogram(const shared_ptr<const ProjDataInfo>& proj_data_info_sptr,
+                  const SinogramIndices&);
+
+  //! Construct sinogram with data set to the array.
+  inline Sinogram(const Array<2,elemT>& p,const shared_ptr<const ProjDataInfo >& proj_data_info_sptr,
+                  const SinogramIndices&);
+
+  //! Construct sinogram from proj_data_info pointer, axial position and segment number.  Data are set to 0.
+  /*!
+    \deprecated Use version with SinogramIndices instead.
+  */
   inline Sinogram(const shared_ptr<const ProjDataInfo>& proj_data_info_ptr, 
                   const int ax_pos_num, const int segment_num); 
 
   //! Construct sinogram with data set to the array.
+  /*!
+    \deprecated Use version with SinogramIndices instead.
+  */
   inline Sinogram(const Array<2,elemT>& p,const shared_ptr<const ProjDataInfo >& proj_data_info_ptr, 
                   const int ax_pos_num, const int segment_num); 
-  
+
+  //! Get indices
+  inline SinogramIndices get_sinogram_indices() const;
   //! Get segment number
   inline int get_segment_num() const; 
   //! Get number of axial positions
@@ -129,8 +147,7 @@ class Sinogram : public Array<2,elemT>
 private:
   
   shared_ptr<const ProjDataInfo> proj_data_info_ptr; 
-  int axial_pos_num;
-  int segment_num;
+  SinogramIndices _indices;
     
 };
 
diff --git a/src/include/stir/Sinogram.inl b/src/include/stir/Sinogram.inl
index 637f9d6ba..e381c6de9 100644
--- a/src/include/stir/Sinogram.inl
+++ b/src/include/stir/Sinogram.inl
@@ -3,6 +3,7 @@
 /*
     Copyright (C) 2000 PARAPET partners
     Copyright (C) 2000- 2007,Hammersmith Imanet Ltd
+    Copyright (C) 2023, University College London
     This file is part of STIR.
 
     SPDX-License-Identifier: Apache-2.0 AND License-ref-PARAPET-license
@@ -28,15 +29,22 @@
 START_NAMESPACE_STIR
 
 
+template <typename elemT>
+SinogramIndices
+Sinogram<elemT>::get_sinogram_indices() const
+{
+  return this->_indices;
+}
+
 template <typename elemT>
 int
 Sinogram<elemT>::get_segment_num() const
-{ return segment_num; }
+{ return this->_indices.segment_num(); }
 
 template <typename elemT>
 int
 Sinogram<elemT>::get_axial_pos_num() const
-{ return axial_pos_num; }
+{ return this->_indices.axial_pos_num(); }
 
 template <typename elemT>
 int
@@ -74,8 +82,8 @@ template <typename elemT>
 Sinogram<elemT>
 Sinogram<elemT>::get_empty_copy(void) const
 {
-    Sinogram<elemT> copy(proj_data_info_ptr, get_axial_pos_num(), get_segment_num());
-    return copy;
+  Sinogram<elemT> copy(proj_data_info_ptr, get_sinogram_indices());
+  return copy;
 }
 
 template <typename elemT>
@@ -89,15 +97,14 @@ template <typename elemT>
 Sinogram<elemT>::
 Sinogram(const Array<2,elemT>& p, 
          const shared_ptr<const ProjDataInfo >& pdi_ptr, 
-         const int ax_pos_num, const int s_num) 
+         const SinogramIndices& ind)
   :
-  Array<2,elemT>(p), 
+  Array<2,elemT>(p),
   proj_data_info_ptr(pdi_ptr),
-  axial_pos_num(ax_pos_num), 
-  segment_num(s_num)
+  _indices(ind)
 {
-  assert(axial_pos_num <= proj_data_info_ptr->get_max_axial_pos_num(segment_num));
-  assert(axial_pos_num >= proj_data_info_ptr->get_min_axial_pos_num(segment_num));
+  assert(axial_pos_num <= proj_data_info_ptr->get_max_axial_pos_num(ind.segment_num()));
+  assert(axial_pos_num >= proj_data_info_ptr->get_min_axial_pos_num(ind.segment_num()));
   // segment_num is already checked by doing get_max_axial_pos_num(s_num)
 
   assert( get_min_view_num() == pdi_ptr->get_min_view_num());
@@ -111,20 +118,33 @@ Sinogram(const Array<2,elemT>& p,
 template <typename elemT>
 Sinogram<elemT>::
 Sinogram(const shared_ptr<const ProjDataInfo >& pdi_ptr, 
-         const int ax_pos_num, const int s_num) 
+         const SinogramIndices& ind)
   :
   Array<2,elemT>(IndexRange2D (pdi_ptr->get_min_view_num(),
 			       pdi_ptr->get_max_view_num(),
 			       pdi_ptr->get_min_tangential_pos_num(),
 			       pdi_ptr->get_max_tangential_pos_num())), 
   proj_data_info_ptr(pdi_ptr),
-  axial_pos_num(ax_pos_num),
-  segment_num(s_num)
+  _indices(ind)
 {
-  assert(axial_pos_num <= proj_data_info_ptr->get_max_axial_pos_num(segment_num));
-  assert(axial_pos_num >= proj_data_info_ptr->get_min_axial_pos_num(segment_num));
+  assert(axial_pos_num <= proj_data_info_ptr->get_max_axial_pos_num(ind.segment_num()));
+  assert(axial_pos_num >= proj_data_info_ptr->get_min_axial_pos_num(ind.segment_num()));
   // segment_num is already checked by doing get_max_axial_pos_num(s_num)
 }
 
+template <typename elemT>
+Sinogram<elemT>::
+Sinogram(const Array<2,elemT>& p,
+         const shared_ptr<const ProjDataInfo >& pdi_sptr,
+         const int ax_pos_num, const int s_num) 
+  : Sinogram(p, pdi_sptr, SinogramIndices(ax_pos_num, s_num))
+{}
+
+template <typename elemT>
+Sinogram<elemT>::
+Sinogram(const shared_ptr<const ProjDataInfo >& pdi_sptr,
+         const int ax_pos_num, const int s_num) 
+  : Sinogram(pdi_sptr, SinogramIndices(ax_pos_num, s_num))
+{}
 
 END_NAMESPACE_STIR
diff --git a/src/include/stir/ViewSegmentNumbers.h b/src/include/stir/ViewSegmentNumbers.h
index 40bdb6c8c..d482487c9 100644
--- a/src/include/stir/ViewSegmentNumbers.h
+++ b/src/include/stir/ViewSegmentNumbers.h
@@ -34,6 +34,10 @@ START_NAMESPACE_STIR
 class ViewSegmentNumbers : public ViewgramIndices
 {
   using ViewgramIndices::ViewgramIndices;
+public:
+  ViewSegmentNumbers(const ViewgramIndices& ind)
+    : ViewgramIndices(ind)
+  {}
 };
 
 END_NAMESPACE_STIR
diff --git a/src/include/stir/Viewgram.h b/src/include/stir/Viewgram.h
index c6dcce6b1..faaf9f7b1 100644
--- a/src/include/stir/Viewgram.h
+++ b/src/include/stir/Viewgram.h
@@ -4,6 +4,7 @@
     Copyright (C) 2000 PARAPET partners
     Copyright (C) 2000 - 2007-10-08, Hammersmith Imanet Ltd
     Copyright (C) 2011-07-01 - 2012, Kris Thielemans
+    Copyright (C) 2023, University College London
     This file is part of STIR.
 
     SPDX-License-Identifier: Apache-2.0 AND License-ref-PARAPET-license
@@ -28,7 +29,8 @@
 
 
 #include "stir/Array.h"
-#include "stir/ProjDataInfo.h" 
+#include "stir/ProjDataInfo.h"
+#include "stir/ViewgramIndices.h"
 #include "stir/IndexRange.h"
 #include "stir/shared_ptr.h"
 
@@ -39,7 +41,7 @@ START_NAMESPACE_STIR
   \ingroup projdata
   \brief A class for 2d projection data.
 
-  This represents a subset of the full projection. segment_num and view_num 
+  This represents a subset of the full projection. SegmentIndices and view_num 
   are fixed.
   
 */
@@ -60,15 +62,31 @@ class Viewgram : public Array<2,elemT>
 #endif
 
 public:
+  //! Construct from proj_data_info pointer and indices. Data are set to 0.
+  inline Viewgram(const shared_ptr<const ProjDataInfo>& proj_data_info_ptr,
+                  const ViewgramIndices& ind);
+
+  //! Construct with data set to the array.
+  inline Viewgram(const Array<2,elemT>& p,const shared_ptr<const ProjDataInfo>& proj_data_info_sptr,
+                  const ViewgramIndices& ind);
+
   //! Construct from proj_data_info pointer, view and segment number. Data are set to 0.
+  /*!
+    \deprecated Use version with ViewgramIndices instead
+  */
   inline Viewgram(const shared_ptr<const ProjDataInfo>& proj_data_info_ptr, 
                   const int v_num, const int s_num); 
 
   //! Construct with data set to the array.
+  /*!
+    \deprecated Use version with ViewgramIndices instead
+  */
   inline Viewgram(const Array<2,elemT>& p,const shared_ptr<const ProjDataInfo>& proj_data_info_ptr, 
                   const int v_num, const int s_num); 
   
 
+  //! Get indices
+  inline ViewgramIndices get_viewgram_indices() const;
   //! Get segment number
   inline int get_segment_num() const; 
   //! Get number of views
@@ -128,8 +146,7 @@ class Viewgram : public Array<2,elemT>
 private:
   
   shared_ptr<const ProjDataInfo> proj_data_info_sptr;
-  int view_num;
-  int segment_num;  
+  ViewgramIndices _indices;
 };
 
 END_NAMESPACE_STIR
diff --git a/src/include/stir/Viewgram.inl b/src/include/stir/Viewgram.inl
index 7dd883893..d8327d9f6 100644
--- a/src/include/stir/Viewgram.inl
+++ b/src/include/stir/Viewgram.inl
@@ -16,6 +16,7 @@
 /*
     Copyright (C) 2000 PARAPET partners
     Copyright (C) 2000- 2009, Hammersmith Imanet Ltd
+    Copyright (C) 2023, University College London
     This file is part of STIR.
 
     SPDX-License-Identifier: Apache-2.0 AND License-ref-PARAPET-license
@@ -27,15 +28,22 @@
 
 START_NAMESPACE_STIR
 
+template <typename elemT>
+ViewgramIndices
+Viewgram<elemT>::get_viewgram_indices() const
+{
+  return this->_indices;
+}
+
 template <typename elemT>
 int
 Viewgram<elemT>::get_segment_num() const
-{ return segment_num; }
+{ return this->_indices.segment_num(); }
 
 template <typename elemT>
 int
 Viewgram<elemT>::get_view_num() const
-{ return view_num; }
+{ return this->_indices.view_num(); }
 
 template <typename elemT>
 int
@@ -74,7 +82,7 @@ template <typename elemT>
 Viewgram<elemT>
 Viewgram<elemT>::get_empty_copy(void) const
   {
-    Viewgram<elemT> copy(proj_data_info_sptr, get_view_num(), get_segment_num());
+    Viewgram<elemT> copy(proj_data_info_sptr, get_viewgram_indices());
     return copy;
 }
 
@@ -90,17 +98,17 @@ template <typename elemT>
 Viewgram<elemT>::
 Viewgram(const Array<2,elemT>& p, 
 	 const shared_ptr<const ProjDataInfo>& pdi_sptr,
-	 const int v_num, const int s_num) 
+         const ViewgramIndices& ind)
   :
   Array<2,elemT>(p), proj_data_info_sptr(pdi_sptr),
-  view_num(v_num), segment_num(s_num)
+  _indices(ind)
 {
   assert(view_num <= proj_data_info_sptr->get_max_view_num());
   assert(view_num >= proj_data_info_sptr->get_min_view_num());
   // segment_num is already checked by doing get_max_axial_pos_num(s_num)
 
-  assert( get_min_axial_pos_num() == pdi_sptr->get_min_axial_pos_num(s_num));
-  assert( get_max_axial_pos_num() == pdi_sptr->get_max_axial_pos_num(s_num));
+  assert( get_min_axial_pos_num() == pdi_sptr->get_min_axial_pos_num(ind.segment_num()));
+  assert( get_max_axial_pos_num() == pdi_sptr->get_max_axial_pos_num(ind.segment_num()));
   assert( get_min_tangential_pos_num() == pdi_sptr->get_min_tangential_pos_num());
   assert( get_max_tangential_pos_num() == pdi_sptr->get_max_tangential_pos_num());
 }
@@ -108,20 +116,35 @@ Viewgram(const Array<2,elemT>& p,
 template <typename elemT>
 Viewgram<elemT>::
 Viewgram(const shared_ptr<const ProjDataInfo>& pdi_sptr,
-	 const int v_num, const int s_num) 
+         const ViewgramIndices& ind)
   : 
-  Array<2,elemT>(IndexRange2D (pdi_sptr->get_min_axial_pos_num(s_num),
-			       pdi_sptr->get_max_axial_pos_num(s_num),
+  Array<2,elemT>(IndexRange2D (pdi_sptr->get_min_axial_pos_num(ind.segment_num()),
+			       pdi_sptr->get_max_axial_pos_num(ind.segment_num()),
 			       pdi_sptr->get_min_tangential_pos_num(),
 			       pdi_sptr->get_max_tangential_pos_num())),
   proj_data_info_sptr(pdi_sptr),
-  view_num(v_num),
-  segment_num(s_num)
+  _indices(ind)
 {
   assert(view_num <= proj_data_info_sptr->get_max_view_num());
   assert(view_num >= proj_data_info_sptr->get_min_view_num());
   // segment_num is already checked by doing get_max_axial_pos_num(s_num)
 }
 
+template <typename elemT>
+Viewgram<elemT>::
+Viewgram(const Array<2,elemT>& p, 
+	 const shared_ptr<const ProjDataInfo>& pdi_sptr,
+	 const int v_num, const int s_num) 
+  :
+  Viewgram(p, pdi_sptr, ViewgramIndices(v_num, s_num))
+{}
+
+template <typename elemT>
+Viewgram<elemT>::
+Viewgram(const shared_ptr<const ProjDataInfo>& pdi_sptr,
+	 const int v_num, const int s_num) 
+  :
+  Viewgram(pdi_sptr, ViewgramIndices(v_num, s_num))
+{}
 
 END_NAMESPACE_STIR
diff --git a/src/swig/stir_projdata.i b/src/swig/stir_projdata.i
index be38c4f0f..e49a52721 100644
--- a/src/swig/stir_projdata.i
+++ b/src/swig/stir_projdata.i
@@ -54,12 +54,19 @@ ADD_REPR(stir::DetectionPosition, %arg(*$self))
 #endif
 %template(DetectionPositionPair) stir::DetectionPositionPair<unsigned int>;
 
-%attributeref(stir::Bin, int, segment_num);
+%attributeref(stir::SegmentIndices, int, segment_num);
+#ifdef STIR_TOF
+%attributeref(stir::SegmentIndices, int, timing_pos_num);
+#endif
+%attributeref(stir::ViewgramIndices, int, view_num);
+%attributeref(stir::SinogramIndices, int, axial_pos_num);
 %attributeref(stir::Bin, int, axial_pos_num);
-%attributeref(stir::Bin, int, view_num);
 %attributeref(stir::Bin, int, tangential_pos_num);
 %attributeref(stir::Bin, int, time_frame_num);
 %attribute(stir::Bin, float, bin_value, get_bin_value, set_bin_value);
+%include "stir/SegmentIndices.h"
+%include "stir/ViewgramIndices.h"
+%include "stir/SinogramIndices.h"
 %include "stir/Bin.h"
 #ifdef STIR_TOF
 ADD_REPR(stir::Bin, %arg(*$self))