Giacomo M. Bisio

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A variety of computational tasks in early vision can be formulated through lattice networks. The cooperative action of these networks depends on the topology of interconnections, both feedforward and recurrent ones. This paper shows that it is possible to consider a distinct general architectural solution for all recurrent computations of any given order.(More)
A new approach to analog VLSI implementations of algorithms for visual cortical processing is presented. Speciically, we introduce a massively parallel architecture , organized as a planar resistive network with voltage controlled current generators locally connected to model interaction schemata responsible of speciic sensitivities in cortical neurons. We(More)
A perceptual human-machine interface based on visual appearance of hand movements is presented. Gestures are defined as the temporal evolution of 3D poses the of user's hand. Each gesture is described by five temporal sequences corresponding to the time evolution of the stereo depth information at the finger-tips. To this end feature processing directly(More)
A variety of computational tasks in early vision can be formulated through lattice networks. The cooperative action of these networks depends upon the topology of interconnections, both feedforward and recurrent ones. The Gabor-like impulse response of a 2nd-order lattice network (i.e. with nearest and next-to-nearest interconnections) is analysed in(More)
The spatial organization of cortical axon and dendritic fields could be an interesting structural paradigm to obtain a functional specificity without postulating highly specific feedforward connections. In this article, we investigate the functional implications of recurrent intracortical inhibition when it occurs through clustered medium-range(More)
We present a cortical-like strategy to obtain reliable estimates of the motions of objects in a scene toward/away from the observer (motion in depth), from local measurements of binocular parameters derived from direct comparison of the results of monocular spatiotemporal filtering operations performed on stereo image pairs. This approach is suitable for a(More)
A cortical model for motion-in-depth selectivity of complex cells in the visual cortex is proposed. The model is based on a time extension of the phase-based techniques for disparity estimation. We consider the computation of the total temporal derivative of the time-varying disparity through the combination of the responses of disparity energy units. To(More)
The characteristics and performance of a hierarchical neural architecture, inspired by models of mammalian visual cortex, are considered. The visual pathway from sensory space to the intermediate (cortical) representation is structured in three layers, with intra and interlayer connections through feedforward and recurrent pathways. These interconnections(More)
A linear architectural model of cortical simple cells is presented. The model evidences how mutual inhibition, occurring through synaptic coupling functions asymmetrically distributed in space, can be a possible basis for a wide variety of spatio-temporal simple cell response properties, including direction selectivity and velocity tuning. While spatial(More)