I've been using this sample to create a "zoomable" content: http://code.msdn.microsoft.com/windowsapps/Scrolling-panning-and-47d70d4c
My HTML:
<div id="zoomElement" class="zoomElement ManipulationContainer">
<img id="zoomContent" class="zoomContent" alt="" src="sample.jpg" />
</div>
My CSS:
.zoomElement {
overflow: auto;
-ms-content-zooming: zoom;
-ms-scroll-rails: none;
-ms-content-zoom-limit-min: 20%;
-ms-content-zoom-limit-max: 500%;
}
Now, no matter what, I've been unable to center the img in its container when it's unzoomed.