enh: ensure ifft with padding works with 3D stack

qpretrieve/fourier/base.py

@@ -245,7 +245,8 @@ def filter(self, filter_name: str, filter_size: float,
             fft_filtered = self.fft_origin * filt_array
             px = int(freq_pos[0] * self.shape[-2])
             py = int(freq_pos[1] * self.shape[-1])
-            fft_used = np.roll(np.roll(fft_filtered, -px, axis=-2), -py, axis=-1)
+            fft_used = np.roll(np.roll(
+                fft_filtered, -px, axis=-2), -py, axis=-1)
             if scale_to_filter:
                 # Determine the size of the cropping region.
                 # We compute the "radius" of the region, so we can
@@ -263,16 +264,18 @@ def filter(self, filter_name: str, filter_size: float,
                     fft_used = fft_used[:, cslice, cslice]
 
             field = self._ifft(np.fft.ifftshift(fft_used))
-            if len(self.origin.shape) != 2:
-                # todo: this must be corrected
-                self.padding = False
+
             if self.padding:
                 # revert padding
-                sx, sy = self.origin.shape
+                sx, sy = self.origin.shape[-2:]
                 if scale_to_filter:
                     sx = int(np.ceil(sx * 2 * crad / osize))
                     sy = int(np.ceil(sy * 2 * crad / osize))
-                field = field[:sx, :sy]
+                if len(fft_used.shape) == 2:
+                    field = field[:sx, :sy]
+                elif len(fft_used.shape) == 3:
+                    field = field[:, :sx, :sy]
+
                 if scale_to_filter:
                     # Scale the absolute value of the field. This does not
                     # have any influence on the phase, but on the amplitude.

tests/test_cupy_gpu/test_oah_from_qpimage_cupy.py

@@ -5,6 +5,27 @@
 from qpretrieve.fourier import FFTFilterCupy3D, FFTFilterCupy, FFTFilterNumpy
 
 
+def test_get_field_compare_FFTFilters(hologram):
+    data1 = hologram
+
+    holo1 = qpretrieve.OffAxisHologram(data1,
+                                       fft_interface=FFTFilterNumpy,
+                                       padding=False)
+    kwargs = dict(filter_name="disk", filter_size=1 / 3)
+    res1 = holo1.run_pipeline(**kwargs)
+
+    holo1 = qpretrieve.OffAxisHologram(data1,
+                                       fft_interface=FFTFilterCupy,
+                                       padding=False)
+    kwargs = dict(filter_name="disk", filter_size=1 / 3)
+    res2 = holo1.run_pipeline(**kwargs)
+
+    assert res1.shape == (64, 64)
+    assert res2.shape == (64, 64)
+    assert not np.all(res1 == res2)
+    assert np.allclose(res1, res2)
+
+
 def test_get_field_cupy3d(hologram):
     data1 = hologram
     data_rp = np.array([data1, data1, data1, data1, data1])
@@ -25,30 +46,25 @@ def test_get_field_cupy3d(hologram):
 
     assert not np.all(res1[0] == res2)
 
-    # import matplotlib.pyplot as plt
-    # fig, axes = plt.subplots(3, 1)
-    # ax1, ax2, ax3 = axes
-    # ax1.imshow(np.abs(res1[0]))
-    # ax2.imshow(np.abs(res2))
-    # ax3.imshow(np.abs(res2)-np.abs(res1[0]))
-    # plt.show()
-
 
-def test_get_field_compare_FFTFilters(hologram):
+def test_get_field_cupy3d_scale_to_filter(hologram):
     data1 = hologram
+    data_rp = np.array([data1, data1, data1, data1, data1])
 
-    holo1 = qpretrieve.OffAxisHologram(data1,
-                                       fft_interface=FFTFilterNumpy,
-                                       padding=False)
-    kwargs = dict(filter_name="disk", filter_size=1 / 3)
+    holo1 = qpretrieve.OffAxisHologram(data_rp,
+                                       fft_interface=FFTFilterCupy3D,
+                                       padding=True)
+    kwargs = dict(filter_name="disk", filter_size=1 / 3,
+                  scale_to_filter=True)
     res1 = holo1.run_pipeline(**kwargs)
-    assert res1.shape == (64, 64)
 
-    holo1 = qpretrieve.OffAxisHologram(data1,
-                                       fft_interface=FFTFilterCupy,
-                                       padding=False)
-    kwargs = dict(filter_name="disk", filter_size=1 / 3)
-    res2 = holo1.run_pipeline(**kwargs)
-    assert res2.shape == (64, 64)
+    holo2 = qpretrieve.OffAxisHologram(data1,
+                                       fft_interface=FFTFilterNumpy,
+                                       padding=True)
+    kwargs = dict(filter_name="disk", filter_size=1 / 3,
+                  scale_to_filter=True)
+    res2 = holo2.run_pipeline(**kwargs)
 
-    assert not np.all(res1 == res2)
+    assert res1.shape == (5, 18, 18)
+    assert res2.shape == (18, 18)
+    assert np.allclose(res1[0], res2)