  Hardware based image processing offers speed and convenience not found in
software-centric approaches. Here, we show theoretically that a two-dimensional
periodic array of dipole-coupled elliptical nanomagnets, delineated on a
piezoelectric substrate, can act as a dynamical system for specific image
processing functions. Each nanomagnet has two stable magnetization states that
encode pixel color (black or white). An image containing black and white pixels
is first converted to voltage states and then mapped into the magnetization
states of a nanomagnet array with magneto-tunneling junctions (MTJs). The same
MTJs are employed to read out the processed pixel colors later. Dipole
interaction between the nanomagnets implements specific image processing tasks
such as noise reduction and edge enhancement detection. These functions are
triggered by applying a global strain to the nanomagnets with a voltage dropped
across the piezoelectric substrate. An image containing an arbitrary number of
black and white pixels can be processed in few nanoseconds with very low energy
cost.
