animations now work + tests

packages/python/plotly/plotly/express/_imshow.py

@@ -364,7 +364,6 @@ def imshow(
         args["animation_frame"] = "plane"
         slice_through = True
 
-    print("slice_through", slice_through)
     # Default behaviour of binary_string: True for RGB images, False for 2D
     if binary_string is None:
         if slice_through:
@@ -382,7 +381,11 @@ def imshow(
 
     # -------- Contrast rescaling: either minmax or infer ------------------
     if contrast_rescaling is None:
-        contrast_rescaling = "minmax" if img.ndim == 2 else "infer"
+        contrast_rescaling = (
+            "minmax"
+            if (img.ndim == 2 or (img.ndim == 3 and slice_through))
+            else "infer"
+        )
 
     # We try to set zmin and zmax only if necessary, because traces have good defaults
     if contrast_rescaling == "minmax":
@@ -436,10 +439,8 @@ def imshow(
 
     # For 2D+RGB data, use Image trace
     elif (
-        img.ndim == 3
-        and (img.shape[-1] in [3, 4] or (slice_through and binary_string))
-        or (img.ndim == 2 and binary_string)
-    ):
+        img.ndim >= 3 and (img.shape[-1] in [3, 4] or slice_through and binary_string)
+    ) or (img.ndim == 2 and binary_string):
         rescale_image = True  # to check whether image has been modified
         if zmin is not None and zmax is not None:
             zmin, zmax = (
@@ -455,15 +456,16 @@ def imshow(
                     img, in_range=(zmin[0], zmax[0]), out_range=np.uint8
                 )
             else:
-                img_rescaled = np.dstack(
+                img_rescaled = np.stack(
                     [
                         rescale_intensity(
                             img[..., ch],
                             in_range=(zmin[ch], zmax[ch]),
                             out_range=np.uint8,
                         )
                         for ch in range(img.shape[-1])
-                    ]
+                    ],
+                    axis=-1,
                 )
             if slice_through:
                 img_str = [
@@ -485,10 +487,19 @@ def imshow(
                         ext=binary_format,
                     )
                 ]
-            traces = [go.Image(source=img_str_slice, name=str(i)) for i, img_str_slice in enumerate(img_str)]
+            traces = [
+                go.Image(source=img_str_slice, name=str(i))
+                for i, img_str_slice in enumerate(img_str)
+            ]
         else:
             colormodel = "rgb" if img.shape[-1] == 3 else "rgba256"
-            traces = [go.Image(z=img, zmin=zmin, zmax=zmax, colormodel=colormodel)]
+            if slice_through:
+                traces = [
+                    go.Image(z=img_slice, zmin=zmin, zmax=zmax, colormodel=colormodel)
+                    for img_slice in img
+                ]
+            else:
+                traces = [go.Image(z=img, zmin=zmin, zmax=zmax, colormodel=colormodel)]
         layout = {}
         if origin == "lower":
             layout["yaxis"] = dict(autorange=True)
@@ -546,5 +557,5 @@ def imshow(
     if labels["y"]:
         fig.update_yaxes(title_text=labels["y"])
     configure_animation_controls(args, go.Image, fig)
-    #fig.update_layout(template=args["template"], overwrite=True)
+    # fig.update_layout(template=args["template"], overwrite=True)
     return fig

packages/python/plotly/plotly/tests/test_core/test_px/test_imshow.py

@@ -327,11 +327,29 @@ def test_facet_col(facet_col, binary_string):
         facet_col_wrap=facet_col_wrap,
         binary_string=binary_string,
     )
-    if facet_col is not None:
-        nslices = img.shape[facet_col]
-        ncols = int(facet_col_wrap)
-        nrows = nslices // ncols + 1 if nslices % ncols else nslices // ncols
-        nmax = ncols * nrows
-        assert "yaxis%d" % nmax in fig.layout
-        assert "yaxis%d" % (nmax + 1) not in fig.layout
-        assert len(fig.data) == nslices
+    nslices = img.shape[facet_col]
+    ncols = int(facet_col_wrap)
+    nrows = nslices // ncols + 1 if nslices % ncols else nslices // ncols
+    nmax = ncols * nrows
+    assert "yaxis%d" % nmax in fig.layout
+    assert "yaxis%d" % (nmax + 1) not in fig.layout
+    assert len(fig.data) == nslices
+
+
+@pytest.mark.parametrize("animation_frame", [0, 1, 2, -1])
+@pytest.mark.parametrize("binary_string", [False, True])
+def test_animation_frame_grayscale(animation_frame, binary_string):
+    img = np.random.randint(255, size=(10, 9, 8)).astype(np.uint8)
+    fig = px.imshow(img, animation_frame=animation_frame, binary_string=binary_string,)
+    nslices = img.shape[animation_frame]
+    assert len(fig.frames) == nslices
+
+
+@pytest.mark.parametrize("animation_frame", [0, 1, 2])
+@pytest.mark.parametrize("binary_string", [False, True])
+def test_animation_frame_rgb(animation_frame, binary_string):
+    img = np.random.randint(255, size=(10, 9, 8, 3)).astype(np.uint8)
+    fig = px.imshow(img, animation_frame=animation_frame, binary_string=binary_string,)
+    print(binary_string)
+    nslices = img.shape[animation_frame]
+    assert len(fig.frames) == nslices