ome-zarr.js

Some JavaScript utils for simple rendering of OME-Zarr images.

About

See the Documentation pages for more details and demos.

To test thumbnail rendering of a sample image, the easiest option is to try https://ome.github.io/ome-ngff-validator/ which uses ome-zarr.js to display a thumbnail.

We use https://github.com/manzt/zarrita.js for loading zarr data.

Supports all versions of OME-Zarr v0.1 -> v0.5.

The URL must point to a multiscales image (not a plate or bioformats2raw.layout group).

Usage

render() uses rendering settings from the omero metadata if the zarr image has it and the lowest resolution of the multiscales pyramid by default:

import * as omezarr from "https://cdn.jsdelivr.net/npm/ome-zarr.js@latest/+esm";

const url = "https://livingobjects.ebi.ac.uk/idr/zarr/v0.4/idr0062A/6001240.zarr";
let src = await omezarr.render(url);
document.getElementById("thumbnail").src = src;

We can choose to use different resolutions of the multiscales pyramid, to apply rendering settings and to render a smaller region of the image. See docs above for more details.

Demo and Development

The index.html page contains a demo of the features described above and can be viewed with:

$ npm install
$ npm run dev

To develop and build the docs, we need to build ome-zarr.js first so it can be imported from /dist/ by the docs:

$ npm run build
$ npm run docs:dev

Typescript from ome-zarr-models-py

I have experimented with using https://github.com/phillipdupuis/pydantic-to-typescript to generate typescript interfaces from https://github.com/ome-zarr-models/ome-zarr-models-py.

The src/types/ome.ts file was generated with:

$ pydantic2ts --module src/ome_zarr_models/v04/image.py --output ome.ts

License

Distributed under the terms of the BSD license, "ome-zarr.js" is free and open source software.

Release steps

• Fetch origin/main, checkout main and rebase
• Bump version in package.json
• Update CHANGELOG.md
• Commit changes

Then:

$ npm run build

# check the docs are up to date (images are rendering correctly)
$ npm run docs:build
$ npm run docs:preview

$ npm pack
$ npm publish

$ git tag v0.0.14
$ git push origin HEAD v0.0.14