Make Paganin processor work with one angle

CHANGELOG.md

@@ -25,6 +25,7 @@
     - Make Binner accept accelerated=False (#1887)
   - Changes that break backwards compatibility:
     - CGLS will no longer automatically stop iterations once a default tolerance is reached. The option to pass `tolerance` will be deprecated to be replaced by `optimisation.utilities.callbacks` (#1892)
+    - Make Paganin Processor work with AcquistionData with one angle (#1920)
 
 * 24.1.0
   - New Features:

Wrappers/Python/cil/processors/PaganinProcessor.py

@@ -224,8 +224,11 @@ def process(self, out=None):
 
         # make slice indices to get the projection
         slice_proj = [slice(None)]*len(data.shape)
-        angle_axis = data.get_dimension_axis('angle')
-        slice_proj[angle_axis] = 0
+        if 'angle' in data.dimension_labels:
+            angle_axis = data.get_dimension_axis('angle')
+            slice_proj[angle_axis] = 0
+        else:
+            angle_axis = None
 
         if data.geometry.channels>1:
             channel_axis = data.get_dimension_axis('channel')
@@ -236,18 +239,16 @@ def process(self, out=None):
         data_proj = data.as_array()[tuple(slice_proj)]
 
         # create an empty axis if the data is 2D
-        if len(data.shape) == 2:
+        if data.geometry.dimension == '2D':
             data.array = np.expand_dims(data.array, len(data.shape))
             slice_proj.append(slice(None))
             data_proj = data.as_array()[tuple(slice_proj)]
+            if len(out.shape) == 2:
+                out.array = np.expand_dims(out.array, len(out.shape))
 
-        elif len(data_proj.shape) == 2:
-            pass
-        else:
+        if len(data_proj.shape) != 2:
             raise(ValueError('Data must be 2D or 3D per channel'))
 
-        if len(out.shape) == 2:
-            out.array = np.expand_dims(out.array, len(out.shape))
 
         # create a filter based on the shape of the data
         filter_shape = np.shape(data_proj)
@@ -275,7 +276,8 @@ def process(self, out=None):
             # loop over the projections
             for i in tqdm(range(len(data.geometry.angles))):
 
-                slice_proj[angle_axis] = i
+                if angle_axis is not None:
+                    slice_proj[angle_axis] = i
                 padded_buffer.fill(0)
                 padded_buffer[slice_pad] = data.array[(tuple(slice_proj))]
 
@@ -294,11 +296,17 @@ def process(self, out=None):
                     padded_buffer[:] = ifft2(fI*self.filter).real
 
                 if data.geometry.channels>1:
-                    out.fill(padded_buffer[slice_pad], angle = i, 
-                             channel=j)
+                    if len(data.geometry.angles)>1:
+                        out.fill(padded_buffer[slice_pad], angle = i, 
+                                channel=j)
+                    else:
+                        out.fill(padded_buffer[slice_pad], channel=j)
                 else:
-                    out.fill(padded_buffer[slice_pad], angle = i)
-
+                    if len(data.geometry.angles)>1:
+                        out.fill(padded_buffer[slice_pad], angle = i)
+                    else:
+                        out.fill(padded_buffer[slice_pad])
+
         data.array = np.squeeze(data.array)
         out.array = np.squeeze(out.array)
         return out

Wrappers/Python/test/test_DataProcessor.py

@@ -3085,6 +3085,29 @@ def test_PaganinProcessor_2D(self):
         output = processor.get_output(override_geometry={'propagation_distance':1})
         self.assertLessEqual(quality_measures.mse(output, thickness), 0.05)
 
+    def test_PaganinProcessor_1angle(self):
+        data = self.data_cone.get_slice(angle=1)
+        data.geometry.config.units = 'm'
+        wavelength = (constants.h*constants.speed_of_light)/(40000*constants.electron_volt)
+        mu = 4.0*numpy.pi*1e-2/(wavelength) 
+        thickness = -(1/mu)*numpy.log(data)
+
+        processor = PaganinProcessor(pad=10)
+        processor.set_input(data)
+        output = processor.get_output(override_geometry={'propagation_distance':1})
+        self.assertLessEqual(quality_measures.mse(output, thickness), 0.05)
+
+        # check with different data order
+        data.reorder(('horizontal','vertical'))
+        wavelength = (constants.h*constants.speed_of_light)/(40000*constants.electron_volt)
+        mu = 4.0*numpy.pi*1e-2/(wavelength) 
+        thickness = -(1/mu)*numpy.log(data)
+
+        processor = PaganinProcessor(pad=10)
+        processor.set_input(data)
+        output = processor.get_output(override_geometry={'propagation_distance':1})
+        self.assertLessEqual(quality_measures.mse(output, thickness), 0.05)
+
 
 if __name__ == "__main__":