Zoom OpenSeadragon is an implementation of OpenSeadragon, an open-source, web-based viewer for high-resolution zoomable images, implemented in pure JavaScript, for desktop and mobile.
It allows to create zoomable galleries from standart wordpress images as well as from deepzoom images.
You can see live demo here
Zoom OpenSeadragon is released under the New BSD license
This plugin is available for download to be used on your WordPress self-hosted installation.