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, and conformance to the IIIF spec.
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.
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.
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.
Special thanks to Jessica Dussault (@jduss4) for providing the hand-drawn "Gocutus" logo, and Greg Tunink (@techgique) for various digital refinements to said logo.