Examination Slide Viewer

Benjamin Gilbert bgilbert at cs.cmu.edu
Thu Jan 9 16:45:12 EST 2014

On 01/09/2014 11:31 AM, Jim Fishback wrote:
> I would like to be able to put a virtual slide (or a smaller extract)
> into an exam document (either XML or HTML), then have the student open
> it in a web viewer. In order to test their knowledge of histopathology,
> I would then like them to click on pre-identified “hotspots” that
> demonstrate they know what they are looking at. I currently use SnagIt
> routinely for generating static jpeg image hotspots, but nobody seems to
> have a similar program that will work with svs files. Does anyone know
> of any such program or capability?

You could probably build this fairly easily.  We use OpenSeadragon for 
web viewing of slide files; see example here:


OpenSeadragon reads image tiles in Deep Zoom format (among others), so 
you would need to generate a Deep Zoom tree from your slide file.  You 
can use VIPS to generate a complete Deep Zoom tree, or use OpenSlide 
Python to generate individual tiles on demand.  (If many students will 
be looking at the same set of slides, it probably makes sense to 
generate the whole tree in advance.)

Then you just need to register for OpenSeadragon canvas-click events:


and compare the click coordinates with your list of regions.  You would 
also need to set zoomPerClick to 1 to disable zooming on single-clicks.

Make sense?

--Benjamin Gilbert

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