OmeZarrImageSource

A multiscale image opened from an OME-Zarr store.

Instances are created with fromHttp or fromFileSystem rather than the constructor. Both factories read the store's metadata up front so the returned source already knows its axes, resolution levels, and channel count. OME-Zarr versions 0.4 and 0.5 are supported and the version is detected from metadata when not given.

A source is handed to a layer which streams chunks from it on demand.

const source = await OmeZarrImageSource.fromHttp({
  url: "https://example.com/image.ome.zarr",
});

const layer = new ImageLayer({
  source,
  sliceCoords: { t: 0, z: 0, c: [0] },
});

Types

SourceDimensionMap

Per-axis dimension metadata for a multiscale image source.

Maps the spatial axes x, y, z and the non-spatial axes c and t onto the source's stored dimensions.

Property	Description
x: SourceDimension	The x spatial dimension.
y: SourceDimension	The y spatial dimension.
z?: SourceDimension	The z spatial dimension if present.
c?: SourceDimension	The channel dimension if present.
t?: SourceDimension	The time dimension if present.
numLods: number	Number of levels of detail in the pyramid.

SourceDimension

One dimension of a multiscale image source.

Property	Description
name: string	Axis name from the source metadata.
index: number	Position of the axis in the stored arrays.
unit?: string	Physical unit if declared in the metadata.
lods: SourceDimensionLod[]	Per-LOD metadata ordered finest first.

SourceDimensionLod

Metadata for one dimension at one level of detail.

Combines array metadata with the OME-Zarr coordinate transform.

Property	Description
size: number	Extent of the dimension in array elements.
chunkSize: number	Chunk extent along the dimension in elements.
scale: number	World units per array element.
translation: number	World coordinate of the first element.

HttpOmeZarrImageSourceProps

Input to OmeZarrImageSource.fromHttp.

Property	Description
url: string	URL of the OME-Zarr root group.
version?: OmeZarrVersion	OME-Zarr version. Detected from metadata when omitted.

FileSystemOmeZarrImageSourceProps

Input to OmeZarrImageSource.fromFileSystem.

Property	Description
directory: FileSystemDirectoryHandle	Directory handle with read permission.
version?: OmeZarrVersion	OME-Zarr version. Detected from metadata when omitted.
path?: `/${string}`	Image path within the directory. Defaults to the root.

Properties

location

The zarr store location the image was opened from.

readonly location: Location<Readable>;

version?

The OME-Zarr version passed at creation if any.

readonly optional version?: "0.5" | "0.4";

Accessors

loader OmeZarrImageLoader

The chunk loader that streams this image's data.

get loader(): OmeZarrImageLoader;

Methods

getDimensions() SourceDimensionMap

Returns per-axis dimension metadata for the image.

Each axis entry lists one record per level of detail with its size, chunk size, scale, and translation. Use these to convert between array indices and world coordinates, pick slice coordinates, and frame cameras around the image extent.

getDimensions(): SourceDimensionMap;

getChannelCount() number

Returns the number of channels in the image.

getChannelCount(): number;

fromHttp() Promise<OmeZarrImageSource>

Opens an OME-Zarr image over HTTP(S).

static fromHttp(props): Promise<OmeZarrImageSource>;

Parameter	Description
props: HttpOmeZarrImageSourceProps	The store url and optional version.

fromFileSystem() Promise<OmeZarrImageSource>

Opens an OME-Zarr image from a local directory.

Uses the File System Access API so it only works in Chromium-based browsers. Pass the handle returned by window.showDirectoryPicker(). The optional path lets an application ask once for root permission and open many images.

static fromFileSystem(props): Promise<OmeZarrImageSource>;

Parameter	Description
props: FileSystemOmeZarrImageSourceProps	The directory handle, optional version, and path.