OME-Zarr Collections support

[will-moore]

Use Case

This is an early heads-up on a future feature request...

The OME-Zarr RFC-8 "Collections" spec is being proposed at ome/ngff#343.

Although it's early days, and the spec has yet to be defined, the proposal is to use Zarr group to define collections of OME-Zarr images. This can include nested collections along with attributes of each "Node" (image). e.g. (from the PR above):

{
    "ome": {
        "version": "0.x",
        "type": "collection",
        "name": "jrc_hela-1",
        "nodes": [{
            "name": "raw",
            "type": "multiscale", // image or collection
            "path": "./raw", // a relative or absolute path
            "attributes": {    
                "example-viewer:settings": {
                    "isDisabled": true
                },
                "other-viewer:voxelType": "intensities"
                ... // arbitrary user-defined metadata
            },
        }, {
            "name": "..",
            "type": "collection",
            "path": "./nested_collection.json"
        }, ... ],
        "attributes": {
            ...
        }
    }
}

OME-Zarr collections may be used for "grids" or images (e.g. HCS data) or a gallery of Images and a bunch of other use cases.

It would be great if BFF could read this data.

Suggest a Solution

BFF would need to be able to read the JSON, and use it to populate the DuckDB (instead of loading csv/parquet). Ideally it would be able to arrange the various attributes for each node into a table.

Additional Details

It would be good to discuss this at the Zurich NGFF Hackathon cc @toloudis

[toloudis]

Similarly, this is also a possible new way for BFF to export image selections to other tools like VolE ... both tools will likely want to support this.

[SeanDuHare]

Related to #584