This is cool.

I made something similar years ago. The primary motivation was my need to print small resolution images in poster sizes when camera technology hadn't gotten to the point they had high enough resolution.

Mine used transparent images as the "shapes" and then it would "stamp" the shapes onto a larger image. It could use multiple shapes in a single image.

Here's an example.

http://imgur.com/gallery/nUUo9

Doesn't look nearly as nice, but maybe someone with more creatively than me could create shapes that make it much more interesting. Anyone have any interest in a library that does that?