IIIF

A sample and quite dumb web server to serve pictures following the iiif API.

Image API Compliance Level 2 is reached.

Setup

libvips is required by bimg.

$ make deps
$ make

$ bin/iiif config.toml

$ DEBUG=iiif,bimg go test -v github.com/greut/iiif/iiif

IIIF image API 2.1

The API specifications can be found on iiif.io.

Identifier

• filepath: the path of the file
• url: the URL of the file (double // is replaced with a simple /)
• base64(url): the URL of the file (encoded using base64)

Region

• full: the full image
• square: a square area in the picture (centered)
• x,y,w,h: extract the specified region (as pixels)
• pct:x,y,w,h: extract the specified region (as percentages)
• smart: attempt to select the center of interest (subject to change as it is not part of IIIF)

Size

• full: the full image (deprecated)
• max: the full image
• w,h: a potentially deformed image of w x h
• !w,h: a non-deformed image of maximum w x h
• w,: a non-deformed image with w as the width
• ,h: a non-deformed image with h as the height
• pct:n: a non-deformed image scaled by n percent

Rotate

• n a clockwise rotation of n degrees
• !n a flip is done before the rotation

limitations bimg only supports rotations that are multiples of 90.

Quality

• color image in full colour
• gray image in grayscale
• bitonal image in either black or white pixels (not supported)
• default image returned in the server default quality

Format

• jpg
• png
• webp
• tiff

limitations : bimg (libvips) doesn't support writing to gif, jp2 or pdf.

Profile

It provides all informations but the available sizes and tiles. The sizes information would be much better linked with a Cache system.

Level2 profile

It provides meta-informations about the service. (incomplete)

Viewers

Some viewers are supporting the iiif API out of the box. The following are included.

• OpenSeadragon
• Leaflet-IIIF
• IiifViewer

Features

Download

By adding ?dl to any image, it will trigger the Content-Disposition with attachement and download the file (ref). Otherwise, the Save as command will take a non-default.png filename.

HTTP

• Cache-Control by default 1 year (the maximum value for HTTP/1.1).
• ETag based on the full identifier (server independent).
• Last-Modified headers based on the filesystem information or current time.

TODO

• Adapt region for max when maxWidth, maxHeight and/or maxArea are specified.

Friendly projects

• thisisaaronland/go-iiif
• h2non/imaginary

Protobuf

$ go get -u github.com/golang/protobuf/protoc-gen-go
$ PATH=$PATH:`pwd`/bin protoc --go_out=. iiif/image.proto