Can a sequential thinning algorithm be parallelized?

It is commonly presumed that only parallel thinning algorithms can be efficiently implemented on a parallel machine. In this paper it is shown that also a sequential thinning algorithm can have parallel features which can be made explicit and successfully used for a parallel implementation. To this end, the main phases of a fully sequential algorithm are reformulated in such a way that each phase can be carried out by using parallel operators. Experimental results, obtained on a general purpose SIMD machine, are finally discussed