Ex Pulvere

This image is generated by starting with randomly allocated unique colours and then swapping adjacent pixels when the swap generally decreases the distances among pixels of similar colours.

Pixels can only move one step at a time and compete with each other along the paths to their desired locations, so that many get stuck, isolated in areas of a generally different colour.

Many other pixels end up gathering together in the same area where pixels of a different colour also gather together, so that the shapes they form are smoothly entangled or interleaved with each other.

These features give the image an overall dusty look.

The image takes an extremely long time to form and this may be a reason for its significant variety of shapes, despite the simple criterion used to swap pixels.

In particular, because of boundary conditions, different shapes tend to emerge at the corners, the borders and the centre of the image.

Image Licence: Public Domain (CC0).