The Spread filter swaps each pixel in the active layer or selection with another randomly chosen pixel by a user specified amount. It works on color transitions, not on plain color areas. No new color is introduced.
This preview displays interactively changes before they are applied to the image.
You can set the distance that pixels will be moved along Horizontal and Vertical axis. The axis can be locked by clicking the Chain icon. You can also define the Unit to be used.