fix duplicate kwargs error + add test

Signed-off-by: maximsmol <1472826+maximsmol@users.noreply.github.com>
plotly · maximsmol · Oct 11, 2024 · Oct 11, 2024 · Oct 11, 2024 · Oct 11, 2024
commit ba98e7e260b1a70e6211dd82c0704a54e346013c
diff --git a/packages/python/plotly/_plotly_utils/data_utils.py b/packages/python/plotly/_plotly_utils/data_utils.py
@@ -53,6 +53,8 @@ def image_array_to_data_uri(
         backend_kwargs = {}
 
     if backend == "pypng":
+        backend_kwargs.setdefault("compression", compression)
+
         ndim = img.ndim
         sh = img.shape
         if ndim == 3:
@@ -62,7 +64,6 @@ def image_array_to_data_uri(
             sh[0],
             greyscale=(ndim == 2),
             alpha=alpha,
-            compression=compression,
             **backend_kwargs,
         )
         img_png = from_array(img, mode=mode)
@@ -71,6 +72,12 @@ def image_array_to_data_uri(
             w.write(stream, img_png.rows)
             base64_string = prefix + base64.b64encode(stream.getvalue()).decode("utf-8")
     else:  # pil
+        if ext == "png":
+            backend_kwargs.setdefault("compress_level", compression)
+
+        if ext == "webp":
+            backend_kwargs.setdefault("lossless", True)
+
         if not pil_imported:
             raise ImportError(
                 "pillow needs to be installed to use `backend='pil'. Please"
@@ -90,8 +97,6 @@ def image_array_to_data_uri(
             pil_img.save(
                 stream,
                 format=ext,
-                compress_level=compression,
-                lossless=True,
                 **backend_kwargs,
             )
             base64_string = prefix + base64.b64encode(stream.getvalue()).decode("utf-8")

diff --git a/packages/python/plotly/plotly/tests/test_optional/test_px/test_imshow.py b/packages/python/plotly/plotly/tests/test_optional/test_px/test_imshow.py
@@ -354,6 +354,15 @@ def test_imshow_backend(backend):
     assert np.all(decoded_img == img_rgb)
 
 
+@pytest.mark.parametrize("lossless", [True, False])
+def test_imshow_backend_kwargs(lossless):
+    fig = px.imshow(img_rgb, binary_backend_kwargs={"lossless": lossless})
+    decoded_img = decode_image_string(fig.data[0].source)
+
+    if lossless:
+        assert np.all(decoded_img == img_rgb)
+
+
 @pytest.mark.parametrize("level", [0, 3, 6, 9])
 def test_imshow_compression(level):
     _, grid_img = np.mgrid[0:10, 0:100]