Characterization of the human visual system threshold performance by a weighting function in the Gabor domain
J. Malo, A.M. Pons, A. Felipe and J.M. Artigas
Journal of Modern Optics, Vol. 44, 1, pp 127-144 (1997)


As evidenced by many physiological and physiological reports, the receptive fields of the first-stage set of mechanisms of the visual process fit to 2D compactly supported harmonic functions. The application of this set of band-pass filter functions to the input signal implies that the human visual system (HVS) performs some kind of conjoint space/spatial frequency transform. In this paper we present a procedure to obtain the linear characterization of the HVS performance in any conjoint domain from the classical linear characterization in the Fourier domain. We have called this weighting function (in the particular case of the Gabor transform) the Gabor stimuli Sensitivity Function (GSF) by analogy with the usually employed weighting function in the Fourier domain: the Contrast Sensitivity Function (CSF). The accuracy of the procedure is proved showing the equivalence between some experimental 2D CSFs and the corresponding GSFs. The main adventage of this new characterization is that a weighting function in a space/spatial frequency domain can account for spatially variant behaviour, which cannot be included in a unique CSF, so a single GSF would be needed to include extra-foveal and large eccentricity behaviour. One example is given of how non-homogeneous systems can be easily characterized in this way.

Key Words: Gabor functions. Linear Perception Model.

References: 40

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