Image API Compliance, 1.0


1. Introduction

This document is a companion to the International Image Interoperability Framework Image API Specification, version 1.0. It defines the set of supported parameters that correspond to different levels of compliance to the IIIF Image API.

2. Compliance Level Summary

Three levels of compliance are defined. Level 0 is defined as the minimum set of supported parameters and features to qualify an implementation of the service as compliant to the IIIF standard. Level 1 is defined as the RECOMMENDED set of parameters and features to be implemented.

Level 0 Level 1 Level 2 Optional
Region
  full x x x
  x,y,w,h x x
  pct:x,y,w,h
x
Size
  full x x x
  w, x x
  ,h x x
  pct:x x x
  w,h x
  !w,h x
Rotation
  0 x x x
  90,180,270 x x
  arbitrary x
Quality
  native x x x
  color x
  grey x
  bitonal x
Format
  jpg x x
  jp2 x
  png x
  tif x
  gif x
  pdf x
Image Information  Request
  json response x x x
  xml response x x x

3. Level 0 Compliance

Servers indicate compliance with level 0 by including the following header in IIIF responses:
Link: <http://library.stanford.edu/iiif/image-api/compliance.html#level0>;rel="profile"

A level 0 compliant image server MAY specify scaling_factors and/or tile_width and tile_height values in the Image information response. At Level 0 compliance, a server is only required to deliver images of sizes computed using the scaling factors declared in the Image Information response. If specified they should be interpreted with the following special meanings:
  • scaling_factors - only the specified scaling factors are supported
  • tile_width, tile_height - clients should request only regions that correspond to output tiles of the specified dimensions
If a client requests an scaling or region outside these parameters then the image server MAY reject the request with a 400 Bad Request error.

4. Level 1 Compliance

Servers indicate compliance with level 1 by including the following header in IIIF responses:
Link: <http://library.stanford.edu/iiif/image-api/compliance.html#level1>;rel="profile"

5. Level 2 Compliance

Servers indicate compliance with level 2 by including the following header in IIIF responses:
Link: <http://library.stanford.edu/iiif/image-api/compliance.html#level2>;rel="profile"