Annotating Gigapixel Images

Comment on Jill's Blog

Gigapixel images are huge. Really huge. They consist of billions of pixels. The upside is that they can capture an insane amount of detail. The downside is that not nearly all of it is visible at once. Annotations are a useful way to provide the viewer with extra information about the image, but how do you make annotations on a massive image in such a way that they are easily readable and don't completely clutter up the screen when you zoom out? This is the issue tackled in this paper by Quing Luan, Steven Drucker, Johannes Kopf, Ying-Qing Xu and Michael Cohen.

Annotations can be put over any sized area of the image. The annotation also has a "depth." At the user zooms in on the image, it appears to the user that they are getting closer to whatever they are zooming in on. The annotations also get larger as the user zooms in. However once the user goes past the "depth" of the annotation, it is no longer displayed. Many annotations have an upper cap on them. That is, they do not appear until the user has zoomed in sufficiently close.

I feel that this is pretty similar to what Google Earth does already. However, I believe this works in real time and and Google Earth doesn't use gigapixel images. I've never worked with gigapixel images but I can see how this would be useful.