Intrinsic 2D features as textons
Erhardt Barth, Christoph Zetzsche, and Ingo Rentschler
Abstract: We suggest that intrinsic-2D (i2D) features, computationally
defined as the outputs of nonlinear operators which model the activity
of end-stopped neurons, play a role in preattentive texture discrimination.
We first show that for discriminable textures with identical power spectra
the predictions of traditional models depend on the type of nonlinearity
and fail for energy measures. We then argue that the concept of intrinsic
dimensionality, and the existence of end-stopped neurons, can help to understand
the role of the nonlinearities. Furthermore, we show examples where models
without strong i2D selectivity fail to predict the correct ranking order
of perceptual segregation. Our arguments regarding the importance of i2D-features
resemble the arguments of Julesz and colleagues on behalf of textons like
terminators and crossings. However, we provide a computational framework
which identifies textons with the outputs of nonlinear operators which
are selective to i2D features.
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