TWITCH   amplifies the background of an image by making it twitch (or increase in saturation or value). A hyper little (or big, if you like) pinch of distortion scurries about the background, ducking behind the foreground.

The background and foreground were differentiated in Photoshop, using magic wand tools and marquees and such to make the mask image shown here. The distortion is all computational.

The applet.
The source.

E'beth pic
E'beth's index screen capture E'beth's index