Status of this Document
This version: 3.0.0
Latest stable version: 3.0.0
1. Introduction
This document is a companion to the IIIF Image API 3.0 Specification. It defines the set of supported parameters that correspond to different levels of compliance to the API.
2. Compliance
Three levels of compliance are defined. Level 0 is the minimum set of parameters and features that must be implemented to qualify the service as compliant with the IIIF Image API Specification. Level 1 is the recommended set of parameters and features to be implemented. Note that servers may not support all combinations of all supported parameters and features, as noted in the appropriate sections below.
In the tables below 
indicates that support is required, and 
indicates that support is optional.
3. Image Parameters
3.1 Region
| Syntax | Feature Name | Level 0 | Level 1 | Level 2 |
|---|---|---|---|---|
full |
|
|
|
|
x,y,w,h |
regionByPx |
|
|
|
pct:x,y,w,h |
regionByPct |
|
|
|
square |
regionSquare |
|
|
|
See also the note under Size about combinations of Size and Region that may not be supported.
3.2 Size
| Syntax | Feature Name | Level 0 | Level 1 | Level 2 |
|---|---|---|---|---|
max |
|
|
|
|
w, |
sizeByW |
|
|
|
,h |
sizeByH |
|
|
|
pct:n |
sizeByPct |
|
|
|
!w,h |
sizeByConfinedWh |
|
|
|
w,h |
sizeByWh |
|
|
|
^size |
sizeUpscaling |
|
|
|
At any level of compliance, an image service whose Image Information response includes the sizes property must support requests for the sizes listed, and a service whose Image Information response includes the tiles property must support requests for the sizes implicit in the width, height and scaleFactors values given for tiles.
Note that servers may express limits on the sizes available for an image with the optional maxWidth, maxHeight and/or maxArea technical properties. Servers are compliant provided they support the forms of the Size parameter shown above for image sizes up to the limits specified. Clients should not assume that the full image at the width and height specified in the Image Information response will be available. The full image will be available at the max size, which might be less than the width and height.
3.3 Rotation
| Syntax | Feature Name | Level 0 | Level 1 | Level 2 |
|---|---|---|---|---|
0 |
|
|
|
|
90,180,270 |
rotationBy90s |
|
|
|
| arbitrary | rotationArbitrary |
|
|
|
!n |
mirroring |
|
|
|
3.4 Quality
| Syntax | Level 0 | Level 1 | Level 2 |
|---|---|---|---|
default |
|
|
|
color |
|
|
(if applicable) |
gray |
|
|
(if applicable) |
bitonal |
|
|
|
3.5 Format
| Syntax | Level 0 | Level 1 | Level 2 |
|---|---|---|---|
jpg |
|
|
|
png |
|
|
|
tif |
|
|
|
gif |
|
|
|
pdf |
|
|
|
jp2 |
|
|
|
webp |
|
|
|
4. HTTP Features
| HTTP Feature | Feature Name | Level 0 | Level 1 | Level 2 |
|---|---|---|---|---|
| base URI redirects | baseUriRedirect |
|
|
|
| CORS | cors |
|
|
|
| json-ld media type | jsonldMediaType |
|
|
|
| profile link header | profileLinkHeader |
|
|
|
| canonical link header | canonicalLinkHeader |
|
|
|
5. Level 0 Compliance
A level 0 compliant image server may specify scaleFactors and/or width and height values for tiles in the Image Information response. At level 0 compliance, a service 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:
scaleFactors- only the specified scaling factors are supportedwidth,heightwithintiles- clients should request only regions that correspond to output tiles of the specified dimensions
A level 0 compliant image server may specify sizes to indicate specific width and height values for sizes available for the full region.
If a client requests a combination of size and region outside these parameters then the image server may reject the request with an error.