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—We present two algorithms for estimating the velocity of a visual stimulus and their implementations with analog circuits using CMOS VLSI technology. Both are instances of so-called token methods, where velocity is computed by identifying particular features in the image at different locations; in our algorithms, these features are abrupt temporal changes(More)
??An integrated circuit with on-chip photoreceptors is described, that computes the bi-directional velocity of a visual stimulus moving along a given axis in the focal plane by measuring the time delay of its detection at two positions. Due to the compactness of the circuit, a dense array of such motion-sensing elements can be monolithically integrated to(More)
We fabricated an improved version of an imager reported earlier [1], primarily by using better pixel circuit and layout principles. The new imager functions over 5 decades of background illumination and has much more symmetrical ON and OFF responses. This imager achieves massive redundancy reduction by temporally differentiating the image contrast. The(More)
We describe a programmable multi-chip VLSI neuronal system that can be used for exploring spike-based information processing models. The system consists of a silicon retina, a PIC microcontroller, and a transceiver chip whose integrate-and-fire neurons are connected in a soft winner-take-all architecture. The circuit on this multi-neuron chip approximates a(More)
We present a multi-chip neuromorphic system in which an Address Event Representation is used for inter-chip communication. The system comprises an analog VLSI transient imager with adaptive photoreceptors, an analog VLSI motion receiver chip and a prototyping communication infrastructure which allows for programmability of connections between the elements(More)
—Detailed processing of sensory information is a computationally demanding task. This is especially true for vision, where the amount of information provided by the sensors typically exceeds the processing capacity of the system. Rather than attempting to process all the sensory data simultaneously, an effective strategy is to focus on subregions of the(More)
We present a CMOS VLSI image sensor containing a 26 × 26 array of differentiating adaptive photoreceptors, combined with a current-mode hysteretic winner-take-all (WTA) network, able to detect and track high-contrast targets moving within its field of view. The device, implemented using standard 0.8 µm CMOS technology, dissipates 600 µW, with a power supply(More)
We present three diierent architectures that make use of analog VLSI velocity sensors for detecting the focus of expansion, time to contact and motion dis-continuities respectively. For each of the architectures proposed we describe the functionality of their component modules and their principles of operation. Data measurements obtained from the VLSI chips(More)