<title>Binary dilation using SKIPSM: some interesting variations</title>

Abstract

The morphological image processing operation of binary dilation, as usually defined, cannot be implemented as a single-pass pipelined operation because it is a 'one-pixel-to- many-pixels' operation, whereas pipelining is possible only for 'one-to-one' or 'many-to-one' operations. Fortunately, there is an indirect equivalent (negate-erode-negate) which can be pipelined, and which can therefore be implemented in either hardware or software using the single-pass SKIPSM FSM (finite-state machine) paradigm. The great speed advantage of SKIPSM, which offers execution time independent of structuring element size, can therefore be extended to binary dilation also. This paper provides a procedure for incorporating these negations into SKIPSM erosion lookup tables, thus creating dilation lookup tables. It also discusses the relationship between FSM initial conditions and image boundary conditions, and 180-degree structuring element rotation. Examples are included.