RAIS Image Server: A IIIF-compliant, 100% open source image server for blazing-fast deep zooming
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Rodent-Assimilated Image Server


RAIS was originally built by eikeon as a 100% open source, no-commercial-products-required, proof-of-concept tile server for JP2 images within chronam.

It has been updated to allow more command-line options, more source file formats, more features, conformance to the IIIF spec, and experimental DeepZoom support.

RAIS is very efficient, completely free, and easy to set up and run. See our wiki pages for more details and documentation.


RAIS uses a configuration system that allows environment variables, a config file, and/or command-line flags. See rais-example.toml for an example of a configuration file. RAIS will use a configuration file if one exists at /etc/rais.toml.

The configuration file's values can be overridden by environment variables, while command-line flags will override both configuration files and environtmental variables. Configuration is best explained and understood by reading the example file above, which describes all the values in detail.

IIIF Features

RAIS supports level 2 of the IIIF Image API 2.1 as well as a handful of features beyond level 2. See the IIIF Features wiki page for an in-depth look at feature support.


RAIS can internally cache the IIIF info.json requests, individual tile requests, and, if it's in use, S3 images to a locally configured location. See the RAIS Caching wiki page for details.

Generating tiled, multi-resolution JP2s

RAIS performs best with JP2s which are generated as tiled, multi-resolution (think "zoom levels") images. Generating images like this is fairly easy with either the openjpeg tools or graphicsmagick. Other tools probably do this well, but we've only directly used those.

You can find detailed instructions on the How to encode jp2s wiki page.



RAIS Image Server is in the public domain under a CC0 license.