Perceptual Coherence : Hearing and Seeing

Surface Textures
Visual Glass Patterns
The Transition Between Noise and Structure 167
Figure 4.9. An array that cannot be segregated based simply on brightness differences
(termed non-Fourier textures). Segregation requires a nonlinear transformation
of firing rates that effectively encodes contrast and not brightness along with a second
linear filter tuned to a lower spatial frequency. Adapted from “A Comparison of the
Dynamics of Simple (Fourier) and Complex (Non-Fourier) Mechanisms in Texture
Segregation,” by A. Sutter and D. Hwang, 1999, Vision Research, 39, 1943–1962.
Glass (1969) introduced a class of texture patterns in which a random dot
pattern is duplicated; the duplication is transformed by rotation, magnification,
or translation and then superimposed onto the original random pattern.
If this process is done over and over again, the superposition of the
original and all the duplicates generates a global “streaky” percept in which