wax:derivatives
There are two tasks namespaced under wax:derivatives, namely wax:derivatives:simple and wax:derivatives:iiif which represent the two options for generating collection image derivatives. You will only run one of these tasks per collection and you should only need to run it once.
wax:derivatives:simple
bundle exec rake wax:derivatives:simple YOUR_COLLECTION_NAME
When you run the line above for your collection, the task will:
-
Look for the directory of source images you specified in your
_config.yml
file undercollections
>YOUR_COLLECTION_NAME
>images
>source
(See: Updating your configuration) -
Generate two copies of each image (full size and thumbnail, with 1140px and 250px widths, respectively) into the directory
img/derivatives/simple
-
Automatically add two fields (
full
andthumbnail
) to each of your metadata records with the relative paths to the image derivatives.
(e.g., bundle exec rake wax:derivatives:simple qatar
)
wax:derivatives:iiif
bundle exec rake wax:derivatives:iiif YOUR_COLLECTION_NAME
When you run the line above for your collection, the task will:
-
Look for the directory of source images you specified in your
_config.yml
file undercollections
>YOUR_COLLECTION_NAME
>images
>source
(See: Updating your configuration) -
Generate many IIIF derivatives, image tiles, and JSON representations of the collection items into the directory
img/derivatives/iiif
. -
Automatically add three fields (
full
,thumbnail
, andmanifest
) to each of your metadata records with the relative paths to the full and thumbnail size image derivatives and the IIIF manifest.
(e.g., bundle exec rake wax:derivatives:iiif qatar
)
Which one should I use?
Simple derivatives
Pros | Cons |
---|---|
Fewer files to create, manage, and host | Doesn’t handle items with multiple images / pdf format |
Loads faster on webpages | Lower quality images, no zooming |
Users can copy/download full images | Users can copy/download full images |
IIIF derivatives
Pros | Cons |
---|---|
Image content is interoperable, meaning it is standardized, (re)usable, and citable broadly (see: https://iiif.io/get-started/how-iiif-works/) | Slow to generate |
Image content can leverage embedded metadata | Slower to load on the page than simple derivatives |
Can handle multiple images / paged content per collection item | Requires the page to use a JS image viewer |
Offers deep zooming of full images with no loss; Images are loaded quickly relative to the high resolution offered | Higher technical overhead, more complex |