FBP split processing respect panel origin

Wrappers/Python/cil/recon/FBP.py

@@ -514,11 +514,12 @@ def _setup_PO_for_chunks(self, num_slices):
         self.data_slice = ag_slice.allocate()
         self.operator = self._PO_class(ig_slice,ag_slice)
 
-    def _process_chunk(self, i, step,  out):
+    def _process_chunk(self, i, step):
         self.data_slice.fill(np.squeeze(self.input.array[:,i:i+step,:]))
         if not self.filter_inplace:
             self._pre_filtering(self.data_slice)
-        out.array[i:i+step,:,:] = self.operator.adjoint(self.data_slice).array[:]
+
+        return self.operator.adjoint(self.data_slice).array
 
 
     def run(self, out=None, verbose=1):
@@ -569,15 +570,32 @@ def run(self, out=None, verbose=1):
             #process dataset by requested chunk size
             self._setup_PO_for_chunks(self.slices_per_chunk)
             for i in range(0, tot_slices-remainder, self.slices_per_chunk):
-                self._process_chunk(i, self.slices_per_chunk, ret)
+
+                if 'bottom' in self.acquisition_geometry.config.panel.origin:
+                    start = i
+                    end = i + self.slices_per_chunk
+                else:
+                    start = tot_slices -i - self.slices_per_chunk
+                    end = tot_slices - i 
+
+                ret.array[start:end,:,:] = self._process_chunk(i, self.slices_per_chunk)
+
                 if verbose:
                     pbar.update(1)
 
             #process excess rows
             if remainder:
-                i = tot_slices-remainder
                 self._setup_PO_for_chunks(remainder)
-                self._process_chunk(i, remainder, ret)
+
+                if 'bottom' in self.acquisition_geometry.config.panel.origin:
+                    start = tot_slices-remainder
+                    end = tot_slices
+                else:
+                    start = 0
+                    end = remainder
+
+                ret.array[start:end,:,:] = self._process_chunk(i, remainder)
+
                 if verbose:
                     pbar.update(1)
 

Wrappers/Python/test/test_reconstructors.py

@@ -652,7 +652,7 @@ def test_results_3D_astra(self):
     def test_results_3D_split(self):
 
         reconstructor = FBP(self.acq_data)
-        reconstructor.set_split_processing(1)
+        reconstructor.set_split_processing(8)
 
         reco = reconstructor.run(verbose=0)
         np.testing.assert_allclose(reco.as_array(), self.img_data.as_array(),atol=1e-3)    
@@ -663,6 +663,27 @@ def test_results_3D_split(self):
         np.testing.assert_allclose(reco.as_array(), reco2.as_array(), atol=1e-8)   
 
 
+    @unittest.skipUnless(has_tigre and has_nvidia and has_ipp, "TIGRE or IPP not installed")
+    def test_results_3D_split_reverse(self):
+
+        acq_data = self.acq_data.copy()
+        acq_data.geometry.config.panel.origin = 'top-left'
+
+        reconstructor = FBP(acq_data)
+        reconstructor.set_split_processing(8)
+
+        expected_image = np.flip(self.img_data.as_array(),0)
+
+        reco = reconstructor.run(verbose=0)
+        np.testing.assert_allclose(reco.as_array(), expected_image,atol=1e-3)    
+
+        reco2 = reco.copy()
+        reco2.fill(0)
+        reconstructor.run(out=reco2, verbose=0)
+        np.testing.assert_allclose(reco.as_array(), reco2.as_array(), atol=1e-8)   
+
+
+
     @unittest.skipUnless(has_tigre and has_nvidia and has_ipp, "TIGRE or IPP not installed")
     def test_results_2D_tigre(self):