Analog VLSI Circuits for the Perception of Visual Motion

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Analog VLSI Implementation

The previous chapter showed how to define optimization problems that describe the computational process of visual motion estimation and how to design appropriate analog networks that solve them. This and the next two chapters now show ways how to actually build such networks as analog integrated circuits. Foremost, I will describe in this chapter the circuit diagram of the optical flow unit, the basic unit of all following network implementations, and discuss its individual building blocks and their properties.

This is a rather technical chapter. The intention was to describe and discuss all building blocks and sub-circuits of the optical flow unit in detail so that the technically interested reader who has access to the necessary technology and tools can, in principle, reproduce the circuits. Or better, adapt and improve them in new designs. Those readers who are not familiar with integrated circuits will find a short primer on basic transistor models and simple circuits in Appendix C. It should be sufficient for a basic understanding of the circuits presented in this chapter. Clearly, a thorough comprehension of the circuit details requires a more profound background. The interested reader is referred to a list of excellent reference books at the end of Appendix C. Although quite technical, the chapter addresses strongly the computational consequences of the chosen way of implementation. The focus of description is on those circuits that have a strong ...