Rendering recognizably unique textures

We present a perceptually designed hardware-accelerated algorithm for generating unique background textures for distinguishing documents. To be recognizable, the texture should produce a random feature vector in the brain after visual feature extraction. Our motivating example is a hypertext user interface which shows a fragment of a link´s target in the margin. Upon traversing the link, the fragment expands to fill the screen. Our goal is to avoid user disorientation by texturing each document with a unique background so that a document can easily be recognized from a fragment. The user should be able to learn the textures of the most often visited documents, as per Zipf´s law. The results of an initial experiment show that the generated textures are indeed recognizable. We discuss a method for enhancing text readability by both providing fast, interactive zooming and unnoticeably bleaching the background around text.