Fig. 1.

Examples of Gabor patches with phase Φ = 0° and Φ = 90°, vertical orientation (Θ = 0°), and spatial frequency F = 2 cpd (Eq. 2). The parameters $h_{\breve{x}}$ and $h_{\breve{y}}$ control the full width at half height (FWHH) of the Gaussian envelope along the directions that are perpendicular and parallel to the grating, respectively.