Earlier today I was pondering the fact that I needed some new business cards when I had a sudden brain storm. A sort of a meta-recursive brainstorm, really. I could picture the design I wanted. But first I’d need some help from Steve Hoelzer.

Who’s Steve Hoelzer? Why he’s the genius behind the MATLAB Annoy-a-tron, but what I’m really interested in is his Droste Effect tool. I could search for it on the File Exchange, but right now I want to take you for a stroll through MATLAB’s Add-On Explorer. Because amazingly enough, you can find Steve’s Droste tool from right inside the heart of a living MATLAB. Not only that, you can install it with one click.

So let’s say you’re using MATLAB and you get a hankering for some Droste magic. On MATLAB’s Home tab, select “Get Add-Ons”.

This will open the Add-On Explorer. Incidentally, they’re called “Add-Ons” because you can add things not only from the File Exchange, but also MathWorks products, like toolboxes and blocksets. Right now we’ll search for the term “droste” and see what that turns up.

Bingo! There’s the file we’re looking for. Click on it so we can learn some more about it. It looks like it’s worth installing. Notice that under the Add button, I can click once and add it to my MATLAB. The Add-On Explorer is also showing me that I’ll need the Image Processing Toolbox in order for this tool to work properly. If I don’t have that toolbox installed, the Add-On Explorer can even guide me through the process of getting a trial.

I add the file to MATLAB, and immediately I’m able to run the code. So here is the effect I’m after: the Droste effect occurs when an image recursively includes itself. Here is the sample image supplied by Steve.

And now you can see my new business card.

If at some point in the future I wanted to remove the Droste Effect tool, I could go up to the Add-On Manager like so.

There I am presented with a list of my current Add-Ons, any one of which I can uninstall.

The Add-On manager opens up a new window on the File Exchange. Discover, add, and manage your files directly from inside MATLAB.