XMLHTTPRequest for IIIF info.json: User specified default image format?

I have been using for a while arrays of info.json requests to load images into the OpenSeadragon viewer, similar to the example here: http://openseadragon.github.io/examples/tilesource-iiif/

This has worked well for most purposes, but now I have a new requirement where I need to preserve the bit depth of the original images in the viewer.world images. The original images are 16-bit depth tif files and using the Cantaloupe IIIF image server I can return 16-bit png and tif files using the IIIF image API image request

{scheme}://{server}{/prefix}/{identifier}/{region}/{size}/{rotation}/{quality}.{format}

by setting the {format} to png or tif

However, the image information request URI ( info.json ) does not provide a way to specify the default format, which is apparently jpg a format that does not support bit depth > 8

How do I go about specifying that the images to be loaded into OSD viewer should be of a particular format as defined in the IIIF image API?

[azaroth42]

That seems like a good enhancement to me. The reason we hard coded .jpg is that it’s the only required format in IIIF, and thus likely to be warm in caches. Thus we don’t have to worry about checking the info.json to see if other formats are also supported and the performance is likely to be better than picking an arbitrary format.

The proposed solution is excellent because it allows per-instance configuration, keeping jpg as the default in the absence of other requirements, such as those of @imoutsatsos 😃 Happy to review and/or provide advice for the IIIFTileSource part … not sure I have bandwidth at the moment to implement.

[iangilman]

@azaroth42 Great; sounds like we’re on the same page… good to have the backstory 😃