We extend the description of a discrete-time cellular neural network, depic
ting the behaviour of both cellular and morphological processors, to any ty
pe of dual-rail processors. We show that a system with two arrays of differ
ential pairs of transceivers can be treated as a two-layer cellular network
and that it can perform morphological and rank order filter operations. As
an illustration we built and tested a dual-rail processor composed of arra
ys of GaAs optical thyristor differential pairs and highlight experimental
results on median filtering.