Spatial summation in simple (fourier) and complex (non-fourier) texture channels

Spatial summation in simple (fourier) and complex (non-fourier) texture channels

Complex (non-Fourier, second-order) channels have been proposed to explain aspects of texture-based region segregation and related perceptual tasks. Complex channels contain two stages of linear filtering with an intermediate pointwise nonlinearity. The intermediate nonlinearity is crucial. Without it, a complex channel is equivalent to a single linear filter (a simple channel). Here we asked w...

A comparison of the dynamics of simple (Fourier) and complex (non-Fourier) mechanisms in texture segregation

Models of texture segregation frequently feature two processing mechanisms: simple, linear channels (1st-order, Fourier mechanisms) and complex channels (2nd-order, non-Fourier mechanisms). Using texture patterns designed to segregate primarily as a result of activity in one set of channels or the other, we employed the method of cued response to obtain speed-accuracy tradeoff (SAT) functions m...

Normalization: contrast-gain control in simple (Fourier) and complex (non-Fourier) pathways of pattern vision

Results from two types of texture-segregation experiments considered jointly demonstrate that the heavily-compressive intensive nonlinearity acting in static pattern vision is not a relatively early, local gain control like light adaptation in the retina or LGN. Nor can it be a late, within-channel contrast-gain control. All the results suggest that it is inhibition among channels as in a norma...

Summation of Fourier Series

A general summability method of different orthogonal series is given with the help of an integrable function θ. As special cases the trigonometric Fourier, Walsh-, Walsh-Kaczmarz-, Vilenkinand Ciesielski-Fourier series and the Fourier transforms are considered. For each orthonormal system a different Hardy space is introduced and the atomic decomposition of these Hardy spaces are presented. A s...

Summation of Fourier