How Quadrupole Convolution WorksTheoretical physics of the 19th century offers hints for vision in the 21st century. |
About the Contents:In places, this explanation bifurcates into streams for readers who are and readers who are not comfortable with equations. These passages are marked as follows:
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The Problem
Vision is based on massive parallel processing,
far beyond our ability to reproduce directly.
Field Theory in Vision
The fields of physics use infinite parallel processing,
and there are good techniques to understand them.
Properties of a Vision Field
Credible postulates about what sort of field might be relevant to vision
give us guidelines from which to infer a field equation.
Laplace’s Equation
Those postulates yield Laplace’s equation, which is easy to solve in two dimensions.
Source of the Field
Laplace’s equation needs a source term to have an interesting solution.
Choice of the Kernel
The kernel gives it the necessary source, driven by the image.
Equation for Linearity
This yields a tractable expression for the linearity.
Emergent Properties of Linearity
The resulting formula has remarkable properties,
far beyond those that were built in during the derivation.
Methods to Evaluate Quadrupole Convolution
Various methods of evaluating linearity give the answers we have seen, and tell us why.