Hey @BioinfoTongLI

Interesting point. We enforce wavelength_id present in Fractal (at least at the moment). Given that the Cellpose task fully functions when the selection happens via label, we should look for a way to relax this.

Given that this model is used in multiple places, the change isn't fully trivial.

Also, my zarr was preprocessed by import_ome_zarr with update_omero_metadata=True.
This is currently not adding wavelength_id if it's missing. We can maybe duplicate label if wavelength_id is not there?

I'd be in favor of adding this to the Import OME-Zarr task as well! Our definition for wavelength_id vs. label is:
A label is a string that describes a channel and that is unique within a given OME-Zarr image and also typically unique across some selections of OME-Zarrs (e.g. all images in a well when those images are separate acquisitions)
A wavelength_id is a string that describes a channel (by some wavelength identifier) and it's unique only within a given image (but e.g. a way to describe the same wavelength in different images where the channels have different names).

We'll probably have to revisit these definitions for the more general, non-HCS cases. I'd be fine with a solution of just adding the label as wavelength_id in the import task if there is no wavelength_id present there