ZOOM RECTANGLE EXAMPLE
The Zoomify Image Viewer supports Alt-click-dragging to create a 'zoom rectangle' over the image (Option-click-dragging on Macintosh).
On release of the mouse the Viewer zooms and pans as needed to fill the display with the area in the rectangle. This feature is available
in the Viewer included in the Pro and Enterprise editions. It is enabled by default in these editions and can be disabled using the HTML parameter zZoomRectangle=0.
On touch devices this feature is not currently enabled - the pinch gesture serves a similar purpose. Also note that
this feature is available when viewing images with or without hotspots or annotations, however,
when editing annotations this feature is available only in Label View mode. It is temporarily disabled
when the Freehand, Polygon, or other Label Mode buttons are clicked.