The digilib IIIF API

The Scaler servlet provides not only its native Scaler API but also an API compliant to the standards of the International Image Interoperability Framework http://iiif.io.

As of version 2.3.7 digilib supports the IIIF Image API version 2 at compliance level 2. You can switch between API version 1.1 and 2.0 support with the iiif-api-version parameter in digilib-config,

IIIF Image API URLs for an image request have the form:

http[s]://{server}/{digilib-webapp}/Scaler/{iiif-prefix}/{identifier}/{region}/{size}/{rotation}/{quality}.{format} 

where digilib-webapp is the name of the digilib web application in the servlet container.

The value of iiif-prefix is defined by the iiif-prefix parameter in digilib-config. The default value is “IIIF”.

The identifier part of the URL must not contain slashes. Since the identifier is mapped to the digilib fn-parameter, which is a filesystem path that likely contains slashes separating subdirectories, all occurrences of a slash have to be replaced by the value of the iiif-slash-replacement parameter in digilib-config. The default value of the replacement string is “!”, so the fn-path “books/book1/page0002” becomes the identifier “books!book1!page0002”.

For a definition of the other parameters region, size, rotation, quality, and format please see the IIIF Image API docs.

A IIIF Image API image request URL could look like:

http://www.example.org/digilib/Scaler/IIIF/books!book1!page0002/full/!150,75/0/default.jpg

An info request URL for the same image looks like:

http://www.example.org/digilib/Scaler/IIIF/books!book1!page0002/info.json