Skeletonization by crystallization

A skeleton of a planar contour is a set of centres of bitangent circles lying inside the contour. If contour of a planar shape was made up of a spatial distribution of sodium acetate crystals the propagating crystallization patterns would implement distance transformation, or thinning, of the contour. In such a case, boundaries between colliding patterns represent skeleton of the planar shape. In laboratory experiments we demonstrate that a supersaturated solution of a sodium acetate is a massively parallel processor. In this sodium-acetate processor data are inputted as spatial distribution of nucleation sites, information is transmitted via propagating patterns of crystallization and results of computation are represented by boundaries between stationary domains of crystals.