Gabor Representations of Spatiotemporal Visual Images

We review Gabor's Uncertainty Principle and the limits it places on the representation of any signal. Representations in terms of Gabor elementary functions (Gaussian-modulated sinusoids), which are optimal in terms of this uncertainty principle, are compared with Fourier and wavelet representations. We also review Daugman's evidence for representations based on two-dimensional Gabor functions in mammalian visual cortex. We suggest three-dimensional Gabor elementary functions as a model for motion selectivity in complex and hypercomplex cells in visual cortex. This model also suggests a computational role for low frequency oscillations (such as the alpha rhythm) in visual cortex.