Fremantle
If you upload TIFF images to the Internet Archive, it will produce JPEG versions of them (e.g.). They'll be the same dimensions, but have a smaller file size. Depending on the complexity of the image, and of course its size, the JPEGs might still be too big for use. They are what gets used in the 'carousel' view that's shown when you open the item's details page, which can be frustrating if there are a bunch of images and each one's JPEG version is a couple of megabytes.
- TIFF derivative URL format:
https://archive.org/download/<ID>/<TIFF base filename>.jpg
Not as frustrating, however, than if you upload PNG images (e.g.). If you do that, IA doesn't create any derivative versions, and will happily try to display the full versions in the carousel. This can make for a very slow browsing experience on the details page if the PNGs are large (e.g. over 100 megabytes).
- PNG derivative URL format:
https://archive.org/download/<ID>/<PNG filename>
The best way to get reasonably-sized derivative images for display seems to be to upload image Zip files. These are created by first ensuring your image files (be they JPEG, TIFF, or PNG) are named so that they appear in the correct order and then zipping them up so they're in the top level of the zip file. The file must then be given a name that ends in _images.zip, and uploaded to IA.
With these the carousel isn't used at all, but instead the bookreader is.
The bookreader shows smaller versions that, if you look at the requests your browser makes,
come from endpoints like https://ia801000.us.archive.org/BookReader/BookReaderImages.php.
This should not be used directly, because it's refering to a specific server;
the OpenLibrary book URL API exists for this purpose.
- Zip derivative URL format:
https://archive.org/download/<ID>/page/leaf<number>_w1000.jpg
The image zip process is easier than producing PDFs locally (e.g.) because many PDF creation processes will modify the embedded images in ways that are not helpful.
My main RSS news feed: https://samwilson.id.au/news.rss
(or Wikimedia.rss, Fremantle.rss, OpenStreetMap.rss, etc. for topic feeds).
Email me at sam or leave a comment below…
samwilson.id.au