fix(napari): 🐛 default view_in_napari to showing every channel

channel=0 as the default silently hid every channel but the first —
surprising for a "let me look at my image" viewer, especially since
it's independent of whichever channel a segmentation ran on (e.g.
Cellpose on channel 0 while the acquisition has 3-4 channels). Default
to channel=None (all channels); pass an int to view just one.

Author: lguerard

docs/guide/ome_zarr_napari.md

@@ -136,13 +136,18 @@ image found under `scan.zarr/labels/`:
 ```python
 from patchworks.plugins.napari import view_in_napari
 
-# auto-loads scan.zarr/labels/* as Labels layers:
+# auto-loads scan.zarr/labels/* as Labels layers, all image channels shown:
 view_in_napari("scan.zarr")
 
 # or point at a separate plain label store written with write_to=:
 view_in_napari("scan.zarr", labels="labels.zarr")
 ```
 
+By default every channel of the image is shown (`channel=None`), independent
+of which one you segmented on — Cellpose might run on channel 0 while you
+still want to see the whole multi-channel acquisition. Pass an int to view
+just one channel instead: `view_in_napari("scan.zarr", channel=0)`.
+
 !!! note
     napari ships in `patchworks[all]`, or install just it with
     `pip install "patchworks[napari]"`.

src/patchworks/plugins/napari.py

@@ -267,7 +267,7 @@ def view_in_napari(
     image: Union[da.Array, str, Path],
     labels: Union[da.Array, str, Path, None] = None,
     *,
-    channel: int | None = 0,
+    channel: int | None = None,
     labels_component: str = "labels",
     image_name: str = "image",
     labels_name: str = "labels",
@@ -290,7 +290,9 @@ def view_in_napari(
         place ``tile_process`` writes them by default — each as its own Labels
         layer. (Falls back to image-only if there are none.)
     channel : int or None, optional
-        Channel to display from the image (``None`` keeps all channels).
+        Channel to display from the image. ``None`` (default) shows every
+        channel — the segmentation channel doesn't need to match what you
+        view. Pass an int to show just that one.
     labels_component : str, optional
         Array name inside a plain-zarr label store (default ``"labels"``,
         matching ``tile_process``'s ``output_component``).