You can setup OpenSeadragon to zoom with a variety of media types[1],
including simple jpgs[2]. But, that said, Jared is correct, you get the
best zooming functionality with tiled images.
Probably an approach to investigate would be extending the Islandora
OpenSeagradon viewer to work with the Basic Image Solution Pack. Might
just be a matter of writing some logic around which content model is
being used with it.
It should also be noted, that we're are using a older version of
OpenSeadragon with Islandora OpenSeadragon, and there are a couple
related JIRA tickets to this[3]. So, our mileage may vary on using that
older version with standalone jpgs.
As for 1702, it might be helpful to look at the CONTRIBUTING.md file,
and look at the feature request section, and flesh out the ticket a bit
more. Might also want to look at the Priority level on it since it is
set to "Trivial".
-nruest
[1]
http://openseadragon.github.io/#examples-and-features
[2]
http://openseadragon.github.io/examples/tilesource-image/
[3]
https://jira.duraspace.org/browse/ISLANDORA-935